Appendix E 

Air Quality Technical Study

In coordination with Oklahoma DOT 

Air Quality

Technical Study 

July 2016 

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Contents 

Acronyms and Abbreviations ................................................................................................................... v 

1.0 Introduction .............................................................................................................................. 1-1 

1.1 Service Type Descriptions .............................................................................................. 1-4

1.1.1 Conventional Rail .......................................................................................................... 1-4 

1.1.2 Higher-Speed Rail ......................................................................................................... 1-4 

1.1.3 High-Speed Rail ............................................................................................................. 1-5 

1.2 Alternative Descriptions ................................................................................................. 1-5

1.2.1 No Build Alternative ...................................................................................................... 1-6 

1.2.2 Northern Section: Oklahoma City to Dallas and Fort Worth ....................................... 1-6 

1.2.3 Central Section: Dallas and Fort Worth to San Antonio ............................................. 1-7 

1.2.4 Southern Section: San Antonio to South Texas .......................................................... 1-9 

1.2.5 Station Cities ............................................................................................................... 1-10 

2.0 Regulatory Context and Purpose ............................................................................................. 2-1 

2.1 Air Pollutants ................................................................................................................... 2-1

2.2 Regulatory Requirements (Laws, Regulations, and Orders) ........................................ 2-3

2.2.1 Federal ........................................................................................................................... 2-3 

2.2.2 State Regulations ......................................................................................................... 2-7 

3.0 Affected Environment .............................................................................................................. 3-1 

3.1 Study Area ....................................................................................................................... 3-1

3.1.1 Northern Section: Oklahoma City to Dallas and Fort Worth ....................................... 3-1 

3.1.2 Central Section: Dallas and Fort Worth to San Antonio ............................................. 3-2 

3.1.3 Southern Section: San Antonio to South Texas .......................................................... 3-3 

3.2 Existing Conditions .......................................................................................................... 3-4

4.0 Impact Evaluation Methods ..................................................................................................... 4-1 

4.1 Types of Effects and Evaluation Approach .................................................................... 4-1

4.1.1 Short-term Construction Effects .................................................................................. 4-1 

4.1.2 Long-Term Regional Effects ......................................................................................... 4-1 

4.1.3 Localized Effects ........................................................................................................... 4-3 

4.1.4 Greenhouse Gas Emissions ......................................................................................... 4-3 

4.2 Intensity of Effects Criteria ............................................................................................. 4-4

4.3 General Conformity ......................................................................................................... 4-5

5.0 Environmental Consequences ................................................................................................. 5-1 

5.1 Overview .......................................................................................................................... 5-1

5.1.1 Short-term Construction Effects .................................................................................. 5-1 

5.1.2 Long-Term Regional Operational Effects ..................................................................... 5-2 

5.1.3 Localized Impacts ......................................................................................................... 5-4 
Contents 

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5.1.4 General Conformity ....................................................................................................... 5-5 

5.2 No Build Alternative ........................................................................................................ 5-5

5.3 Northern Section: Oklahoma City to Dallas and Fort Worth ......................................... 5-6

5.3.1 Alternative N4A Conventional Rail ............................................................................... 5-6 

5.4 Central Section: Dallas and Fort Worth to San Antonio ............................................... 5-6

5.4.1 Alternative C4A Higher-Speed Rail .............................................................................. 5-6 

5.4.2 Alternative C4A High-Speed Rail .................................................................................. 5-7 

5.4.3 Alternative C4B Higher-Speed Rail .............................................................................. 5-8 

5.4.4 Alternative C4B High-Speed Rail .................................................................................. 5-8 

5.4.5 Alternative C4C Higher-Speed Rail .............................................................................. 5-9 

5.4.6 Alternative C4C High-Speed Rail .................................................................................. 5-9 

5.5 Southern Section: San Antonio to South Texas ......................................................... 5-10

5.5.1 Alternative S4 Higher-Speed Rail ............................................................................... 5-10 

5.5.2 Alternative S6 Higher-Speed Rail ............................................................................... 5-11 

5.5.3 Alternative S6 High-Speed Rail .................................................................................. 5-11 

6.0 Potential Mitigation Strategies ................................................................................................ 6-1 

6.1 Construction Phase ......................................................................................................... 6-1

6.2 Operational Phase .......................................................................................................... 6-1

7.0 Subsequent Analysis ................................................................................................................ 7-1 

7.1 Construction and Operation Emissions ......................................................................... 7-1

7.2 Localized Impacts ........................................................................................................... 7-1

7.3 General Conformity ......................................................................................................... 7-1

7.4 Greenhouse Gases and Climate Change ...................................................................... 7-1

8.0 References ............................................................................................................................... 8-1 

Appendix 

A Emission Calculations 

List of Figures 

1-1: Build Alternatives ............................................................................................................................ 1-2

List of Tables 

1-1: Alternatives Carried Forward for Further Evaluation ................................................................... 1-3

1-2: Cities with Potential Stations ....................................................................................................... 1-10

2-1: Ambient Air Quality Standards for Criteria Pollutants ................................................................... 2-3

5-1: Summary of Operational Regional Air Quality Emissions ............................................................. 5-3

 
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Acronyms and Abbreviations 

μg/m3 micrograms per cubic meter 

AAQS ambient air quality standards 

ACOG Association of Central Oklahoma Governments 

BART Best Achievable Retrofit Technologies 

CAA Clean Air Act 

CEQ Council on Environmental Quality 

CFR Code of Federal Regulations 

CO carbon monoxide 

CO2 carbon dioxide 

EDMS Emissions and Dispersion Modeling System 

EIS environmental impact statement 

EPA U.S. Environmental Protection Agency 

FRA Federal Railroad Administration 

GHG greenhouse gas 

HrSR higher-speed rail 

HSR high-speed rail 

I/M Inspection and Maintenance 

MOA Memorandum of Agreement 

MOVES Motor Vehicle Emission Simulator 

MSATs Mobile Source Air Toxics 

NAAQS National Ambient Air Quality Standards 

NEPA National Environmental Policy Act 

NO nitric oxide 

NO2 nitrogen dioxide 

NOx nitrogen oxides 

NCDC National Climatic Data Center 

NOAA National Oceanic and Atmospheric Administration 
Acronyms and Abbreviations 

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O3 ozone 

OAC Oklahoma Administrative Code 

OCS Oklahoma Climatological Survey 

ODEQ Oklahoma Department of Environmental Quality 

Pb lead 

PM particulate matter 

PM10 particulate matter 10 micrometers in diameter or less 

PM2.5 particulate matter 2.5 micrometers in diameter or less 

ppb parts per billion 

ppm parts per million 

Program Texas-Oklahoma Passenger Rail Program 

SIP state implementation plan 

SO2 sulfur dioxide 

SOx sulfur oxides 

Study Texas-Oklahoma Passenger Rail Study 

TAC Texas Administrative Code 

TCEQ Texas Commission on Environmental Quality 

TERP Texas Emissions Reduction Plan 

TxDOT Texas Department of Transportation 

USDOT U.S. Department of Transportation 

VMT vehicle miles traveled 

VOC volatile organic compound 
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1.0 Introduction 

The Texas Department of Transportation (TxDOT), along with the Federal Railroad Administration 

(FRA), is preparing a service-level environmental impact statement (EIS) to evaluate intercity 

passenger rail service alternatives for the Texas-Oklahoma Passenger Rail Program (Program). The 

purpose of the Program is to enhance intercity mobility by providing enhanced passenger rail 

service as a transportation alternative that is competitive with automobile, bus, and air travel. 

Preparation of the service-level EIS, in support of which this technical study has been prepared, is 

one of two primary objectives of the Texas-Oklahoma Passenger Rail Study (Study). In addition to 

the service-level EIS, TxDOT and FRA are preparing a service development plan for the corridor to 

guide further development and capital investment in passenger rail improvements identified in the 

EIS Record of Decision. The Oklahoma Department of Transportation (ODOT) is a partnering state 

agency for the Study and the EIS. 

The 850-mile corridor analyzed for the Study runs north-south and roughly parallels Interstate 

Highway 35 (IH-35), with the northern point in Edmond, Oklahoma (i.e., northern end of the 

Oklahoma City portion of the corridor), and the southern end in south Texas, potentially in Corpus 

Christi, Brownsville, Laredo, or the Rio Grande Valley, as shown on Figure 1-1. For this service-level 

analysis, a preliminary alignment was developed to represent each EIS alternative, based on 

conceptual engineering that considered and avoided obvious physical or environmental constraints. 

These alignments were not refined to optimize performance, reduce cost, avoid specific properties 

or individual environmental resources, or for any other such considerations. If an alternative is 

selected at the service-level for further development, the above considerations would be assessed 

at the project level. For the service-level EIS, a broad corridor of study with a width of 500 feet has 

been identified along each route for most environmental resources being analyzed.1 The 500 footwide EIS Study Area corridor provides an envelope that could accommodate areas for associated 

effects, including necessary roadway shifts, grade separations, construction activities, and affiliated 

features such as stations and parking, traction-power substations, power lines, and maintenanceof-way facilities. This corridor is composed of areas 500 feet on either side of the preliminary 

alignment and is the area used to identify aesthetic and visual resources that could be potentially 

affected by the build alternatives. Typically, county-wide data were collected for counties partially or 

completely within the Study Area. 

The analysis provides quantitative information about air quality within the EIS Study Area for each 

alternative and compares it against the No Build Alternative and other build alternatives in the 

same geographic region. The discussion of effects also provides qualitative differences in 

 

1 Other environmental resource issues, such as transportation, air quality, and noise and vibration, also use broader 

study areas to determine impacts. 
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Figure 1-1: Build Alternatives 
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permanent, temporary, and direct and indirect effects that are associated with the service type 

(conventional rail, higher-speed rail, or high-speed rail) relative to the environmental context. 

However, because the 500-foot EIS Study Area does not represent the actual footprint of operation 

or construction phases, the analysis is primarily comparative, based on the presence of the 

resources within the EIS Study Area and the likelihood of effects as appropriate for this service-level 

analysis. 

The build alternatives are divided into the following three geographic sections based on the key 

regional markets that could be served by passenger rail improvements: 

 Northern Section: Oklahoma City to Dallas and Fort Worth 

 Central Section: Dallas and Fort Worth to San Antonio 

 Southern Section: San Antonio to South Texas 

In addition, the alternatives consist of both a route, which refers to the specific corridor that a 

potential alignment follows, and a service type, which refers to the speed or category of rail 

transportation (conventional rail, higher-speed rail, or high-speed rail). The alternatives that have 

been carried forward for analysis in the EIS, including their geographic sections, routes, and service 

types, are listed in Table 1-1. 

Table 1-1: Alternatives Carried Forward for Further 

Evaluation 

Route Service Typea 

Northern Section 

N4A CONV 

Central Section 

C4A 

HrSR 

HSR 

C4B 

HrSR 

HSR 

C4C HrSR 

HSR 

Southern Section 

S4 HrSR 

S6 HrSR 

HSR 

a CONV = conventional rail (up to 79 to 90 miles per hour [mph]); 

HrSR = higher-speed rail (up to 110 to 125 mph); HSR = high-speed 

rail (up to 220 to 250 mph) 
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The route alternatives were based on the alignments of existing transportation networks with 

corridors potentially suitable for passenger rail operations2 (i.e., the existing railroad network and 

the existing interstate highway network) or they were located on new alignments outside existing 

transportation corridors. Potential alignments described as “following” railway corridors share 

existing tracks, are located within an existing right-of-way, or are generally adjacent to existing 

tracks, depending on the service type. Alternatives that are outside the existing transportation 

corridor could have greater direct and indirect effects than those located in the existing 

transportation corridor; for example, alternatives outside existing corridors could divide 

neighborhoods or wildlife communities or create a potential new barrier. 

1.1 Service Type Descriptions 

The three service types (conventional rail, higher-speed rail, and high-speed rail) considered in this 

EIS are described below. 

1.1.1 Conventional Rail 

Conventional rail typically includes diesel-powered, steel-wheeled trains operating on steel tracks. 

Roadway crossings may be grade-separated depending on the type of roadway and amount of 

traffic, and rail rights-of-way may be fenced. Conventional rail would be operated at speeds up to 

79 to 90 miles per hour (mph) and would mostly use existing railroad rights-of-way. For 

conventional rail alternatives, existing railroad track may be used, or in some cases, modifications 

such as double-tracking could be constructed within the existing right-of-way to accommodate 

additional trains. 

1.1.2 Higher-Speed Rail 

Higher-speed rail is similar to conventional rail in several respects. In many cases, higher-speed rail 

trains can run on the same steel tracks that support conventional rail, but higher speeds can 

require improvements such as upgrading wooden ties with concrete ties, improving signaling, and 

upgrading roadway crossings. In this case, higher-speed rail trains are assumed to be dieselpowered. Higher-speed rail would be operated at speeds up to 110 to 125 mph. Where proposed 

within an existing railroad right-of-way, a shared right-of-way with separate tracks for freight and 

passenger services would be constructed. Because of its maximum speed and because train 

frequency would be similar to conventional rail, higher-speed rail could operate on a single track 

with passing locations and would not require double-tracking. Where higher-speed rail is proposed 

outside an existing transportation corridor, the new alignment would be designed with curves and 

other features that could accommodate high-speed rail service if warranted by ridership and 

 

2 The term “operations” includes maintenance of the facilities as well. 
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economically feasible in the future. However, unlike high-speed rail, the design would not include 

electrification or a full double track, and some grade crossings would remain. 

1.1.3 High-Speed Rail 

High-speed rail includes electric trains powered by an overhead power supply system. Train sets are 

steel wheel on steel rail, but are designed to operate at high speeds with an aerodynamic shape, 

and suspension and braking systems are designed for high-speed travel. High-speed rail would be 

operated at speeds up to 220 to 250 mph. The entire right-of-way would be fenced and fully gradeseparated. The alignment would be electrified and double-tracked. This service type could only 

reach its maximum speeds outside existing transportation corridors because existing railroad 

alignments are not compatible with the speeds required and they do not have the required space 

for separation of freight and high-speed rail. In areas where this service type is within existing 

transportation corridors, it would operate at lower speeds. 

1.2 Alternative Descriptions 

For this service-level analysis, a preliminary alignment was developed to represent each route 

alternative, based on conceptual engineering that considered obvious physical or environmental 

constraints. They are not detailed alignments that have been refined to optimize performance, 

reduce cost, avoid specific properties or individual environmental resources, or similar 

considerations, which would be assessed at the project-level phase for alternatives carried forward 

for further analysis. 

The alternatives evaluated in the service-level EIS, shown on Figure 1-1, have been developed to a 

level of detail appropriate for a service-level analysis: the route alternatives represent a potential 

corridor where rail improvements could be implemented but do not specify the precise location of 

the track alignment. When a route is refined to include a service type (conventional, higher-speed, 

or high-speed rail), it is then referred to as an alternative. Alternatives in the Northern, Central, and 

Southern sections could be built as individual, stand-alone projects or in combination with 

alternatives in another section. In addition, more than one alternative in the Central Section and 

Southern Section could be built in the future because the alternatives provide different service 

types for independent destinations. Details on connecting the alternatives would be determined 

during project-level studies. 

Potential alignments are described below in terms of nearby transportation corridors and cities. 

The Southern Section alternatives include a potential extension to Monterrey, Mexico. The EIS 

evaluates alignment corridors only within the United States; however, the potential extension to 

Monterrey has been included for ridership analysis purposes, and FRA and TxDOT have initiated 

coordination with the Mexican government about the potential extension. 
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1.2.1 No Build Alternative 

The No Build Alternative would not fulfill the Program’s purpose and need but is carried forward as 

a baseline alternative against which the build alternatives are compared. The No Build Alternative 

would consist of the existing transportation network, including roadway, passenger rail, and air 

travel in the Study Vicinity and committed improvements to these systems. The No Build Alternative 

includes existing and planned roadway, passenger rail, and air travel in the Study Vicinity (including 

operation, maintenance, and expansion). Information was collected from current regional 

transportation plans within the Study Vicinity and websites describing services such as train 

schedules. These improvements and their evaluation at this service-level stage would require 

project-specific assessment. 

1.2.2 Northern Section: Oklahoma City to Dallas and Fort Worth 

Due to feasibility based on initial ridership and cost information, only one route alternative with one 

service type was considered feasible in the Northern Section: Alternative N4A with conventional rail. 

1.2.2.1 Alternative N4A Conventional Rail 

Alternative N4A would begin in Edmond, Oklahoma, and follow 

the BNSF rail alignment south to Oklahoma City. The alternative 

would continue south along the BNSF rail alignment to Norman, 

Oklahoma; through Metro Junction, near Denton, Texas; and on 

to Fort Worth (as does the Heartland Flyer). From Fort Worth, 

the alternative would continue east to Dallas following the 

Trinity Railway Express (TRE) tracks. From Edmond to Dallas, 

the route would be approximately 260 miles long. Because 

existing freight traffic would not preclude passenger service 

along this section of track, the route would provide passenger 

rail service on the existing BNSF track, with potential 

improvements within the existing BNSF right-of-way. 

Alternative N4A would provide several improvements over the 

existing Heartland Flyer service. Alternative N4A would increase 

the number of daily round trips along this route (the Heartland 

Flyer currently offers one round trip per day), and the N4A route 

would extend from Fort Worth to Dallas without requiring a 

transfer (the Heartland Flyer service currently terminates in Fort 

Worth). In addition, Alternative N4A would provide improvements to existing station facilities and 

new train equipment with more onboard amenities, including business class available for a 

premium price. 
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Alternative N4A assumes diesel-locomotive hauled equipment running three to six daily round trips. 

Two or three of the round trips would operate on an accelerated schedule, making roughly seven 

stops, with the remaining local trains making up to 12 stops. 

1.2.3 Central Section: Dallas and Fort Worth to San Antonio 

Three route alternatives, each with higher-speed and high-speed rail 

options, were evaluated in the Central Section: Alternatives C4A, C4B, and C4C. 

The Central Section alternatives would provide several improvements over the existing Texas Eagle 

service in this corridor. All of the alternatives would increase the number of daily round trips along 

this route (the Texas Eagle currently offers one round trip per day), The high-speed rail options 

would provide faster service between Dallas and Fort Worth and Antonio — 2 hours versus 8 hours 

for the Texas Eagle Service. In addition, the Central Section alternatives would provide 

improvements to existing station facilities and new train equipment. 

1.2.3.1 Alternative C4A Higher-Speed and High-Speed Rail 

Alternative C4A would begin in Fort Worth and follow the TRE 

tracks east to Dallas. From Dallas, it would follow the BNSF 

alignment south toward Waxahachie where it would enter a new 

alignment outside existing highway and rail corridors to 

accommodate maximum operating speeds. Though outside 

existing transportation corridors, the southern portion of 

Alternative C4A would generally follow the BNSF alignment for 

about 250 miles, traveling south from Waxahachie through 

Hillsboro, Waco, Temple, Taylor, and Austin to San Antonio. 

Alternative C4A Higher-Speed Rail assumes new highperformance diesel-locomotive hauled equipment running six to 

12 daily round trips. Express trains would likely make seven 

stops, and local trains would make up to 12 stops. 

Alternative C4A High-Speed Rail assumes true electric-powered, 

high-speed service running 12 to 20 daily round trips. Express 

trains would likely make six stops, and local trains would make up 

to nine stops. 
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1.2.3.2 Alternative C4B Higher-Speed and High-Speed Rail 

Alternative C4B would serve both Fort Worth and Dallas, with 

trains following a new elevated high-speed rail alignment over 

IH-30. In Arlington (between Dallas and Fort Worth), the 

alternative would turn south to Hillsboro on an alignment outside 

existing transportation corridors. The alternative would then follow 

the same high-speed rail alignment as Alternative C4A from 

Hillsboro to San Antonio. 

Alternative C4B Higher-Speed Rail assumes new highperformance diesel-locomotive hauled equipment running six to 

12 daily round trips. Express trains would likely make seven 

stops, and local trains would make up to 12 stops. 

Alternative C4B High-Speed Rail assumes true electric-powered, 

high-speed service running 12 to 20 daily round trips. Express 

trains would likely make six stops, and local trains would make up 

to eight stops. 

1.2.3.3 Alternative C4C Higher-Speed and High-Speed Rail 

Alternative C4C would follow the same potential alignment as 

Alternative C4A from Fort Worth east to Dallas and south to San 

Antonio, but would include a link from Hillsboro directly to Fort 

Worth parallel to the UPRR alignment. Service on the Alternative 

C4C route would operate in a clockwise direction, running from 

Hillsboro to Fort Worth, to Dallas, back to Hillsboro, and south to 

San Antonio in order to serve Fort Worth directly (while also being 

compatible with the general service for Alternative C4A). 

Alternative C4C Higher-Speed Rail assumes new highperformance diesel-locomotive hauled equipment running six to 

12 daily round trips. Express trains would likely make seven 

stops, and local trains would make up to 12 stops. 

Alternative C4C High-Speed Rail assumes true electric-powered 

high-speed service running 12 to 20 daily round trips. Express 

trains would likely make six stops, and local trains would make up 

to nine stops. 
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1.2.4 Southern Section: San Antonio to South Texas 

Two route alternatives were evaluated in the Southern Section: Alternative S4, with higher-speed 

rail, and Alternative S6, with higher-speed and high-speed rail 

options. 

1.2.4.1 Alternative S4 Higher-Speed Rail 

Alternative S4 Higher-Speed Rail would begin in San Antonio and 

travel southeast along the UPRR alignment to George West, 

where it would continue outside existing transportation corridors 

to Alice. At Alice, the alternative would divide into three legs at a 

stop. The first leg would travel west along the Kansas City 

Southern (KCS) Railway to San Diego, Texas; it would then travel 

outside existing transportation corridors to east of Laredo in an 

alignment that would allow higher speeds and rejoin the KCS 

Railway to enter the highly developed Laredo area. The second 

leg would travel south along abandoned railroad tracks to 

McAllen and east to Harlingen and Brownsville. The third leg 

would travel east along the KCS Railway to Corpus Christi. 

Alternative S4 Higher-Speed Rail assumes new high-performance 

diesel-locomotive hauled equipment running four to six daily 

round trips. Depending on corridor demand model forecasts, the 

primary service may be designated as Laredo-Alice-San Antonio 

and Corpus Christie-Alice-San Antonio, with a connecting feeder 

from Brownsville, Harlingen, and McAllen. 

1.2.4.2 Alternative S6 Higher-Speed and High-Speed Rail 

Alternative S6 would begin in San Antonio and travel south on a 

new alignment outside existing transportation corridors to a 

station near the Laredo-Columbia Solidarity Bridge, which crosses 

the Rio Grande north of Laredo. The alternative would then cross 

on a new railway bridge to join a new rail line being constructed in 

Mexico, which would continue to Monterrey. This study only 

examines the physical effects of the U.S. component of this new 

line, but it does consider the ridership effect of such a 

connection. 

Alternative S6 Higher-Speed Rail assumes new high-performance 

diesel-locomotive hauled equipment running four to six daily 
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round trips between San Antonio and Laredo, which would be the only U.S. stops for the alternative. 

If an extension from Laredo to Monterrey is added, the frequency of trips to Monterrey is assumed 

to be the same as those from San Antonio to Laredo. 

Alternative S6 High-Speed Rail assumes true electric-powered, high-speed service running eight to 

12 daily round trips between San Antonio and Laredo. If an extension from Laredo to Monterrey is 

added, the frequency of trips to Monterrey is assumed to be the same as those from San Antonio to 

Laredo. 

1.2.5 Station Cities 

The study does not evaluate specific station locations, and no conclusion about the exact location 

of stations will be made as part of the service-level EIS process. However, based on ridership data 

and transit connectivity information developed as part of the Alternatives Analysis (TxDOT 2014), 

and based on stakeholder input, the cities in which stations would most likely be located have been 

assumed. The size and design of stations would be appropriate for the service type and the route of 

the alternative. Cities that could have stations are listed in Table 1-2. 

Table 1-2: Cities with Potential Stations 

Oklahoma 

Edmond Pauls Valley 

Oklahoma City Ardmore 

Norman 

Texas 

Gainesville Austin 

Fort Worth San Antonio 

Arlington Alice 

Dallas Corpus Christi 

Waxahachie Harlingen 

Waco McAllen 

Temple (also serving Killeen) Brownsville 

Taylor Laredo 
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2.0 Regulatory Context and Purpose 

The purpose of this air quality technical study is to provide an overview of the meteorological 

conditions and existing monitored air quality conditions in which the proposed project traverses, 

including conformance with ambient air quality standards (AAQS). In addition, this section describes 

the potential impacts resulting from each project alternative during construction and operation that 

may directly and indirectly affect state and regional air quality under the alternatives, using the 

existing and No Build conditions for comparison. 

2.1 Air Pollutants 

Air quality describes the level of pollution in the air. Air pollutants, individually and in combination, 

degrade the atmosphere by reducing visibility, damaging property, reducing the productivity or vigor 

of crops or natural vegetation, or harming human or animal health. 

The U.S. Environmental Protection Agency (EPA) has established National Ambient Air Quality 

Standards (NAAQS) for the following major air pollutants. These pollutants, known as criteria 

pollutants, are carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxides (NO2), ozone (O3), 

particulate matter 10 micrometers or less in diameter (PM10) and particulate matter 2.5 

micrometers or less in diameter (PM2.5), and lead (Pb) (EPA 2016a). CO is a colorless, odorless gas 

that is generated in the urban environment primarily by the incomplete combustion of fossil fuels in 

motor vehicles. Relatively high concentrations of CO can be found near crowded intersections and 

along heavily used roadways carrying slow-moving traffic. CO chemically combines with the 

hemoglobin in red blood cells to decrease the oxygen-carrying capacity of the blood. Prolonged 

exposure can cause headaches, drowsiness, or loss of equilibrium. 

SO2 could be generated by the incomplete combustion of fossil fuels in motor vehicles. However, 

relatively little SO2 is emitted from motor vehicles. The health effects of SO2 include respiratory 

illness, damage to the respiratory tract, and bronchio-constriction. 

NO2 and nitrogen oxide (NO), collectively referred to as NOx, are major contributors to ozone 

formation. NOx could be emitted by motor vehicles. Although NO2 and NO can irritate the eyes and 

nose and impair the respiratory system, NOx is of concern primarily because of its role in the 

formation of ozone. 

Ozone is a photochemical oxidant that is a major cause of lung and eye irritation in urban 

environments. It is formed through a series of reactions involving VOC and NOx that take place in 

the atmosphere in the presence of sunlight. Relatively high concentrations of ozone are normally 

found only in the summer because low wind speeds of stagnant air coupled with warm 

temperatures and cloudless skies provide the optimum conditions for ozone formation. Because of 

the long reaction time involved, peak ozone concentrations often occur far downwind of the 

precursor emissions. Thus, ozone is considered a regional pollutant rather than a localized 

pollutant. 
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Particulate matter includes both airborne and deposited particles of a wide range of size and 

composition. Of particular concern for air quality are PM10 and PM2.5. The data collected through 

many nationwide studies indicate that most PM10 is product of fugitive dust, wind erosion, and 

agricultural and forestry sources, while a small portion is produced by fuel combustion processes. 

However, combustion of fossil fuels account for a significant portion of PM2.5. Airborne particulate 

matter mainly affects the respiratory system. 

Lead is a stable chemical element that persists and accumulates both in the environment and in 

humans and animals. There are many sources of lead pollution, including mobile sources such as 

motor vehicles and other gasoline-powered engines, and non-mobile sources such as petroleum 

refineries. Lead levels in the urban environment from mobile sources have significantly decreased 

due to the federally mandated switch to lead-free gasoline. The principal effects of lead on humans 

are on the blood-forming, nervous, and renal systems. 

The criteria pollutants of concern for transportation-related sources include PM10 and PM2.5 due to 

diesel locomotive emissions (referred to as diesel particulates), CO and NOx due to roadway vehicle 

emissions, and ozone. Ozone is formed through photochemical reactions between precursor gases 

including volatile organic compounds (VOCs) and NOx. Sources of VOCs and NOx include emissions 

from internal combustion engines such as roadway vehicles and diesel locomotives. 

Carbon dioxide (CO2) is a colorless, odorless gas that occurs naturally in the earth’s atmosphere. 

Significant quantities are also emitted into the air by fossil fuel combustion. CO2 is considered a 

greenhouse gas (GHG). The natural greenhouse effect allows the earth to remain warm and sustain 

life. GHGs trap the sun’s heat in the atmosphere and help determine our climate. As atmospheric 

concentrations of GHGs rise, so may temperatures. Higher temperatures may result in more 

emissions, increased smog, and respiratory disease. 

GHGs are also pollutants of concern. These gases trap heat in the atmosphere and are necessary 

to life as we know it because they keep the planet’s surface warm. As concentrations of GHG 

increase, however, the Earth’s temperature rises. This is known as the “Greenhouse Gas Effect.” 

Effects of these rising temperatures include climate change and rising sea levels. With respect to 

transportation‐related sources, such as the diesel trains and personal vehicles of this proposed 

project, and other fossil fuel combustion sources, the GHG of primary concern is CO2. Other GHGs 

of concern include methane, NOx and certain fluorinated gases. 

In addition to the criteria and GHG pollutants, EPA also regulates air toxics. Mobile source air toxics 

(MSATs) are compounds emitted from highway vehicles and non‐road equipment that are known or 

suspected to cause cancer or other serious health and environmental effects. Most air toxics 

originate from human made sources, including on‐road mobile sources, non‐road mobile sources 

(e.g., trains), area sources (e.g., dry cleaners), and stationary sources (e.g., factories or refineries). 
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2.2 Regulatory Requirements (Laws, Regulations, and Orders) 

Air quality is regulated at the federal level by EPA and at the state level by the Texas Commission on 

Environmental Quality (TCEQ) and the Oklahoma Department of Environmental Quality (ODEQ). The 

following section describes the federal and state regulations that are applicable to the proposed 

project. 

2.2.1 Federal 

Clean Air Act and National Ambient Air Quality Standards 

EPA is the federal agency that develops and enforces the regulations that help govern air quality. 

The federal Clean Air Act of 1970 (CAA) and CAA Amendments of 1990 established the NAAQS for 

specific criteria pollutants in 40 Code of Federal Regulations (CFR) Part 50 to protect public health. 

The primary standards are intended to protect the public health with an adequate margin of safety. 

The secondary standards are intended to protect the nation’s welfare and account for air-pollutant 

impacts on soil, water, visibility, vegetation, and other aspects of the general welfare. The primary 

and secondary NAAQS exist for the six criteria pollutants: CO, SO2, NO2, O3, PM10 and PM2.5, and Pb. 

The NAAQS for criteria pollutants are shown in Table 2-1 (EPA 2016a). ODEQ and TCEQ have 

adopted the NAAQS as their state standards (ODEQ 2013a; TCEQ 2014a). 

Table 2-1: Ambient Air Quality Standards for Criteria Pollutants 

Pollutant Primary / 

Secondary 

Concentration 

Averaging Time NAAQS Threshold 

Carbon 

Monoxide (CO) 

Primary 8-hour 9 ppm Not to be exceeded more 

than once per year 1-hour 35 ppm 

Lead (Pb) Primary and 

Secondary 

Rolling 3 month 

averagea 

0.15 μg/m3 Not to be exceeded 

Nitrogen 

Dioxide (NO2) 

Primary 1-hourb 100 ppb 98th percentile, averaged 

over 3 years 

Primary and 

Secondary 

Annualc 53 ppb Annual Mean 

Ozone (O3) Primary and 

Secondary 

8-hour (2015 

Standard)d 

0.070 ppm Annual fourth-highest daily 

maximum 8-hr 

concentration, averaged over 

3 years 
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Pollutant Primary / 

Secondary 

Concentration 

Averaging Time NAAQS Threshold 

Particulate 

Matter (PM2.5) 

Primary Annual 12 μg/m3 weighted annual mean, 

averaged over 3 years 

Secondary Annual 15 μg/m3 annual mean, averaged over 

3 years 

Primary and 

Secondary 

24-hour 35 μg/m3 98th percentile, averaged 

over 3 years 

Particulate 

Matter (PM10) 

Primary and 

Secondary 

24-hour 150 μg/m3 Not to be exceeded more 

than once per year on 

average over 3 years 

Sulfur Dioxide 

(SO2) 

Primary 1-hour 75 ppbe 99th percentile of 1-hour 

daily maximum 

concentrations, averaged 

over 3 years 

Secondary 3-hour 0.5 ppm Not to be exceeded more 

than once per year 

a Final rule signed October 15, 2008. The 1978 lead standard (1.5 μg/m3 as a quarterly average) remains in effect 

until one year after an area is designated for the 2008 standard, except that in areas designated nonattainment for 

the 1978, the 1978 standard remains in effect until implementation plans to attain or maintain the 2008 standard 

are approved. 

b To attain this standard, the 3-year average of the 98th percentile of the daily maximum 1-hour average at each 

monitor within an area must not exceed 100 ppb 

c The official level of the annual NO2 standard is 0.053 ppm, equal to 53 ppb, which is shown here for the purpose of 

clearer comparison to the 1-hour standard. 

d Final rule signed October 26, 2015. 

e Final rule signed June 2, 2010. The 1971 annual and 24-hour SO2 standards were revoked in that same 

rulemaking. However, these standards remain in effect until one year after an area is designated for the 2010 

standard, except in areas designated nonattainment for the 1971 standards, where the 1971 standards remain in 

effect until implementation plans to attain or maintain the 2010 standard are approved. 

μg/m3 = micrograms per cubic meter 

ppb = parts per billion 

ppm = parts per million 

Source: EPA (2016a). 
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The CAA requires EPA to classify areas in the country as attainment or nonattainment, with respect 

to each criteria pollutant, depending on whether the areas meet the applicable NAAQS. Areas 

classified as “attainment areas” comply with the applicable NAAQS. Areas once classified as 

nonattainment that have since demonstrated attainment of the NAAQS are classified as 

“maintenance areas.” Maintenance areas are required to implement the EPA-approved 

maintenance plan to maintain the standard under NAAQS. Areas not in compliance with the NAAQS 

are classified as “nonattainment areas.” 

The CAA requires each state to produce and regularly update a state implementation plan (SIP) for 

each criteria pollutant that violates the applicable NAAQS. SIP is an enforceable plan developed at 

the state level that serves as a tool to avoid and minimize emissions of pollutants to achieve 

compliance with the NAAQS. 

General Conformity 

The EPA Conformity Rule requires federal agencies to ensure that any federal action resulting in 

emissions of any nonattainment or maintenance criteria pollutants conforms with the approved or 

promulgated state or federal implementation plans for attaining or maintaining the NAAQS. 

Specifically, this means ensuring that the federal action will not (1) cause a new violation of NAAQS, 

(2) increase the frequency or severity of existing violations of NAAQS, or (3) delay the timely 

attainment of NAAQS interim or other attainment milestones. The EPA Final Conformity Rule applies 

only to federal actions in NAAQS nonattainment or maintenance areas. 

National Environmental Policy Act 

Signed into law on January 1, 1970, the National Environmental Policy Act (NEPA) requires federal 

agencies to assess the environmental effects of their proposed actions prior to making decisions. In 

1978, the Council on Environmental Quality (CEQ) issued regulations (40 CFR Parts 1500-1508) to 

implement NEPA. These regulations are binding on all federal agencies. The regulations address 

the procedural provisions of NEPA and the administration of the NEPA process, including the 

preparation of environmental assessments and EIS documents to assess the likelihood of impacts 

from alternative courses of action. 

Air Toxics 

In addition to the criteria pollutants, EPA also regulates air toxic emissions. Controlling air toxic 

emissions became a national priority with the passage of the CAA Amendments of 1990, whereby 

Congress mandated that EPA regulates 188 air toxics, also known as hazardous air pollutants. EPA 

has assessed this expansive list in its latest rule on the Control of Hazardous Air Pollutants from 

Mobile Sources (Federal Register, Vol. 72, No. 37, page 8430, February 26, 2007) and identified a 

group of 93 compounds emitted from mobile sources that are listed in its Integrated Risk 

Information System (http://www.epa.gov/iris/). In addition, EPA identified seven compounds with 
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significant contributions from mobile sources that are among the national and regional-scale 

cancer risk drivers from its 1999 National Air Toxics Assessment 

(http://www.epa.gov/ttn/atw/nata1999/); these compounds are acrolein, benzene, 1,3-butidiene, 

diesel particulate matter plus diesel exhaust organic gases (diesel PM), formaldehyde, 

naphthalene, and polycyclic organic matter. While EPA has regulations to limit the emissions of air 

toxics, there are currently no federal or state ambient air quality concentration standards for air 

toxics 

Greenhouse Gases 

In addition to regulating criteria pollutants, in accordance with the CAA Section 202(a) and the Final 

Endangerment and Cause or Contribute Findings, GHG pollutants are also regulated at the federal 

level (EPA 2014). CEQ released revised draft guidance on the consideration of GHG in NEPA 

documents for all federal actions on December 18, 2014. The revised guidance established a 

reference point of 25,000 metric tons of CO2-e emissions on an annual basis, below which a 

quantitative GHG emissions analysis is not warranted (CEQ 2014). The draft CEQ guidance is still 

under review, and currently there is not a quantitative federal threshold to address GHG emissions 

and the impacts on climate change at the project level. 

CO2 is the largest component of these GHG emissions. Historically, GHG emissions have not been 

regulated under the CAA as air pollutants. However, after the U.S. Supreme Court in 2007 clarified 

that CO2 is an "air pollutant" subject to regulation under the CAA, EPA embarked on developing 

requirements and standards for GHG emissions from mobile and stationary sources under the CAA. 

However, currently there are no NAAQS or de minimis thresholds in place for GHG. The following 

summarizes the main GHG regulatory initiatives recently undertaken by EPA in the transportation 

sector. 

 EPA and the National Highway Traffic Safety Administration are taking steps to enable the 

production of a new generation of clean vehicles, through the reduction of GHG emissions and 

improved fuel use. Together, the enacted and proposed standards are expected to save more 

than six billion barrels of oil through 2025 and reduce more than 3,100 million metric tons of 

CO2 emissions (EPA 2016b). 

 EPA is also responsible for developing and implementing regulations to ensure that 

transportation fuel sold in the United States contains a minimum volume of renewable fuel. By 

2022, the Renewable Fuel Standard Program, which was created under the Energy Policy Act of 

2005, anticipates reducing GHG emissions by 138 million metric tons, equivalent to the annual 

emissions of 27 million passenger vehicles (EPA 2016b). 

GHGs are addressed on a regional or national level. Although no ambient air quality standards have 

been established for GHGs, the federal government has established a goal of reducing GHG 
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emissions from transportation related activities. The goal will be attained by implementing the 

following four strategies: 

1. Use low carbon fuels including but not limited to ethanol, biodiesel, natural gas, liquefied 

petroleum gas, synthetic fuels, hydrogen, and electricity; 

2. Increase vehicle fuel efficiency by developing and bringing to market advanced engine and 

transmission designs, lighter-weight materials, improved vehicle aerodynamics, and reduced 

rolling resistance, which would result in lower fuel use (U.S. Department of Transportation 

[USDOT] 2010); 

3. Improve transportation system efficiency through traffic management and bottleneck relief 

as well as lowering speed limits on national highways; 

4. Reduce carbon intensive transit activity by implementing transportation pricing strategies, a 

few examples being a fee per vehicle-mile traveled (VMT) of about 5 cents per mile, an 

increase in the motor fuel tax of about $1.00 per gallon, or pay-as-you-drive insurance. Also 

significant expansion of urban transit services, in conjunction with land use changes and 

pedestrian and bicycle improvements would be included (USDOT 2010). 

To date, no national standards have been established regarding GHGs, nor has EPA established 

criteria or thresholds for ambient GHG emissions pursuant to its authority to establish motor vehicle 

emission standards for CO2 under the CAA. However, there is a considerable body of scientific 

literature addressing the sources of GHG emissions and their impacts on climate, including reports 

from the Intergovernmental Panel on Climate Change, the National Academy of Sciences, EPA, and 

other federal agencies. Given their characteristic rapid dispersion into the global atmosphere, GHGs 

are different from other air pollutants evaluated in federal environmental reviews because the 

impacts are not localized or regional. From a quantitative perspective and in terms of both absolute 

numbers and types, global climate change is the cumulative result of numerous and varied natural 

and anthropogenic emissions sources. Each source makes a relatively small addition to global 

atmospheric GHG concentrations. In contrast to broad-scale actions such as those involving an 

entire industry sector or very large geographic areas, it is difficult to isolate and understand the 

GHG emissions impacts for a particular transportation project (TxDOT 2015). 

2.2.2 State Regulations 

2.2.2.1 Oklahoma 

Air quality is regulated at the state level by the ODEQ as specified by the Oklahoma Administrative 

Code (OAC) Title 252 Chapter 100. Oklahoma has a Regional Haze Implementation Plan consistent 

with federal Prevention of Significant Deterioration regulations to protect the state’s one Class 1 

area, the Wichita Mountains, which are located 60 to 90 miles west of the proposed project area 

(ODEQ 2013b). Oklahoma does not have any areas classified as nonattainment or maintenance 

areas according to the NAAQS. 
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As previously mentioned, ODEQ has adopted the NAAQS as its state standards for the criteria 

pollutants, which are shown in Table 2-1 (ODEQ 2013a). Oklahoma does not have any areas 

classified as being in nonattainment or maintenance in respect to the NAAQS and uses its 

stationary new source review and permitting programs as the foundation of its SIP which is 

approved by the governor in order to maintain compliance with the NAAQS (ODEQ 2014). Although 

all regions of Oklahoma are in attainment or unclassified with the NAAQS, the Association of Central 

Oklahoma Governments (ACOG) participated in the EPA 8-Hour Ozone Flex program to implement 

voluntary reduction measures to control ground level ozone formation and set a 5-year plan in 

place for Central Oklahoma in June 2008 (40 CFR Part 81 Subpart C Section 107). Activities 

associated with the 5-year plan concluded in June 2013. In 2012, ACOG registered with EPA for 

participation in EPA’s Ozone Advance Program where participants have agreed to take proactive 

steps toward improving air quality (ACOG 2012). Programs that are being implemented as a part of 

ACOG’s advance voluntary program are the Oklahoma City metro area’s Compressed Natural Gas 

and Alternative Fuels Programs (EPA 2013). 

Oklahoma currently has two SIP plan revisions pending submission to EPA in regards to the NAAQS 

2008 primary and secondary 8-hour ozone standards and the 2010 primary SO2 standard (ODEQ 

2014). Oklahoma’s Interstate Transport SIP for an Assessment of Oklahoma’s Impact on Downwind 

Nonattainment for the National Ambient 8-hour Ozone and PM2.5 Air Quality Standards, submitted 

to EPA in May 2007 (including supplemental information submitted in November 2007), 

demonstrates that Oklahoma does not have a significant impact on ozone or PM2.5 nonattainment 

for any other state, nor interfere with maintenance of the NAAQS in any other state (ODEQ 2013b). 

Oklahoma also maintains a Regional Haze Implementation Plan that was last revised and 

submitted to EPA on June 18, 2013. The Regional Haze Implementation Plan addresses Best 

Achievable Retrofit Technologies (BART) to address emissions of NO2, SO2 and particulate matter 

(PM) at three power plants (six total coal-fired units). This plan should not affect the project (ODEQ 

2013c). 

2.2.2.2 Texas 

Air quality is regulated at the state level by TCEQ under Texas Administrative Code (TAC) Title 30 

Part 1 Chapters 101 through 122 (TCEQ 2013a). Texas has several areas, especially in Dallas and 

Fort Worth that are nonattainment for one or more NAAQS. 

Texas has developed a SIP to manage emissions on a state-wide and regional basis. Revisions to 

the SIP incorporate changes in regulations and attainment status of regions. The most recent state 

wide revision was the Regional Haze update, which was approved by EPA in March 2014. The 2014 

Five-Year Regional Haze SIP Revision implements further reductions in the NOX emissions caps for 

electricity generating units that go into place in 2015, and continues with clean diesel and motor 

vehicle programs as the primary method to address the 1997 8-hour ozone standard. A new 

attainment deadline has not yet been issued (TCEQ 2014b). The motor vehicle and fuel programs 
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that are implemented by the state of Texas will reduce statewide air pollutant emissions. These 

programs include the Texas Emissions Reduction Plan (TERP), the Vehicle Inspection and 

Maintenance (I/M) Program (TCEQ 2014c), and the Texas Low Emission Diesel Fuel Program 

initially implemented in 2005 (TCEQ 2014d). 

Texas has also adopted SIP revisions that affect only portions of the state. These revisions affecting 

the proposed project areas include the ozone and lead planning activities for the Dallas and Fort 

Worth area, which predominantly target stationary sources in the region; and the Austin-Round 

Rock, San Antonio, and Corpus Christi area ozone planning activities (TCEQ 2014a).

Details of attainment status of Texas are summarized in Table 3-1, in Section 3.0, Affected 

Environment. The Dallas and Fort Worth counties of Denton, Tarrant, Dallas, Johnson, and Ellis are 

designated as moderate nonattainment areas for the 2008 8-hour ozone standard, and serious 

nonattainment for the 1997 8-hour ozone standard. To show progress towards attainment of the 

1997 8-hour ozone standard on July 2, 2014, TCEQ adopted the Attainment Demonstration SIP 

Revision that includes the Dallas and Fort Worth area, a Reasonable Further Progress SIP Revision, 

and revisions to 30 TAC, Chapter 115 into the Texas SIP. EPA approval of these revisions is pending 

(TCEQ 2014e). A portion of Collin County is nonattainment for the 2008 lead standard, and a 

maintenance area for the 1978 lead standard (TCEQ 2013b). 

Areas designated as attainment or unclassified/attainment for the 8-hour ozone standard, as 

published on April 30, 2004 (69 Federal Register 23858) are eligible to participate in EPA’s 8-Hour 

Ozone Flex program. The program is implemented through a voluntary intergovernmental 

agreement (Memorandum of Agreement [MOA]) among EPA, TCEQ, and the local communities. The 

proposed project travels through the city of Austin, which is a participant in the MOA (EPA 2008). 

The Austin-Round Rock Eight-Hour Ozone Flex MOA commits the Austin-Round Rock area to 

continuing the implementation of the Early Action Compact SIP and voluntary emission reduction 

measures. The MOA also includes applying for TERP grants, when available; Transportation 

Emission Reduction Measures; regional rideshare program; inviting five or more additional cities to 

join the area's Clean Air Coalition and becoming signatories to the MOA; implementing a 

watch/warning ozone alert system for the area; implementing AirCheck Texas local initiative 

projects with Low Income Repair Assistance Program funds; and road paving projects. 

For all pollutants, the counties the project traverses in the Southern Section, including San Antonio, 

are in attainment or unclassified (TCEQ 2014a). Corpus Christi was designated as attainment by 

EPA for the 1997 8-hour ozone NAAQS. A five-year agreement was signed in 2007 for Nueces and 

San Patricio Counties to participate in the Ozone Flex program for the 8-hour ozone standard, which 

encourages 8-hour ozone attainment areas nationwide to reduce ozone emissions to continue to 

meet the NAAQS for ozone (EPA 2008; TCEQ 2014a). 
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3.0 Affected Environment 

3.1 Study Area 

The Study Area for air quality impacts is composed of the regional air basins that the Program 

corridor would go through. Air quality in nearby air basins could also be affected by changes in 

travel patterns, VMTs, and regional pollutant transport resulting from the alternatives, but likely at a 

much lower level than in the Program corridor. For this service-level analysis, potential effects on air 

quality are evaluated only for the air basins (i.e., regions) that physically contain the alternatives. 

The origination point of the proposed project in the north is Edmond, Oklahoma, just north of 

Oklahoma City, and a termination point in south Texas, potentially in the cities of Laredo or Corpus 

Christi or the Rio Grande Valley region. Major metropolitan areas are typically the main source of air 

emissions due to large human populations and numbers of vehicles on the roadways, and more 

industry. The proposed project travels through the major metropolitan areas of Oklahoma City, 

Dallas and Fort Worth, Austin, San Antonio, and Corpus Christi. 

3.1.1 Northern Section: Oklahoma City to Dallas and Fort Worth 

The Northern Section of the proposed project begins in Edmond, Oklahoma, travels through 

Oklahoma City and southern Oklahoma across the Texas border, through north central Texas, and 

into the Dallas and Fort Worth area. 

While in central Oklahoma the project is located in the Central Oklahoma Intrastate Air Quality 

Control Region. The largest and most populated metropolitan area in this region is Oklahoma City 

with a relatively flat topography with elevations around 1,200 feet above sea level situated on the 

Canadian River. The climate is influenced by the Great Plains and is characterized by frequent 

winds with long hot summer seasons and shorter milder winters (Oklahoma Climatological Survey 

[OCS] 2014). 

While all of Oklahoma is in attainment or unclassified for all federally regulated pollutants (40 CFR 

Part 81 Subpart C Section 107), ACOG has been proactive in its planning to reduce mobile source 

emissions—cars and trucks—which account for approximately 60 percent of the region’s pollution 

and is currently implementing plans to increase participation in public fleet conversions, the use of 

public transportation and ride sharing programs. ACOG is also participating in EPA’s 8-hour Ozone 

Flex Program to implement voluntary reduction measures to control ground level ozone formation 

(ACOG 2012; EPA 2008). 

From southern Oklahoma to the Texas border, the project travels through the Southeastern 

Oklahoma Intrastate Air Quality Control Region and the counties of Garvin, Murray, Carter, and 

Love. Southern Oklahoma, south of Oklahoma City, consists of primarily rural areas and small cities 

and is characterized by rolling hills and flat lands typical of the Great Plains with elevations ranging 

from approximately 500 to 1,000 feet above sea level. The climate is similar to that found in 

central Oklahoma (U.S. Census, 2013; OCS 2014). 
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From the Texas-Oklahoma border, the proposed alignment travels into north central Texas through 

Cooke County which consists of primarily rural areas and small cities, and into Denton County 

where the project enters the Dallas-Fort Worth-Arlington air basin and metropolitan area that is 

currently designated as nonattainment of ozone. The project travels through Denton, Tarrant, 

Dallas, Johnson, and Ellis counties. This area is the most populated part of the region, with a 

combined population of over 6.8 million (U.S. Census 2013). This region of rolling hills varies in 

elevation from 500 to 800 feet above sea level and is characterized by a humid subtropical climate 

with hot summers; and a continental climate with generally mild winters (National Climatic Data 

Center [NCDC] 2014; National Oceanic and Atmospheric Administration [NOAA] 2014a). 

3.1.2 Central Section: Dallas and Fort Worth to San Antonio 

The Central Section of the proposed project begins in Dallas and Fort Worth, which is discussed 

above and travels through Austin in central Texas and ends in San Antonio in south Texas. 

From the Dallas-Fort Worth-Arlington air basin, the alignment traverses the rural counties of Hill, 

McLennan, Falls, and Bell, and into the Austin-Round Rock air basin through Williamson, Travis, 

and Caldwell counties. 

As the alignment leaves the Dallas-Fort Worth air basin, it enters the into the Austin-Round Rock air 

basin, which is in attainment or unclassified for all air pollutants (TCEQ 2014a). Austin has almost 

900,000 people and is characterized by a humid subtropical climate with hot summers and 

relatively mild winters (U.S. Census 2013; NOAA 2014b). Elevations within the city range from 400 

feet to 1,000 feet above sea level. The winters have temperatures that fall below freezing an 

average of 25 days per year, with strong cold fronts that bring sudden drops in temperature. (NCDC 

2014; NOAA 2014b). 

From the Austin-Round Rock air basin, the proposed project travels along I-35 into the San Antonio 

air basin, traversing Guadalupe and Bexar counties. The San Antonio air basin was designated as 

attainment for the 1997 8-hour ozone standard by EPA on April 2, 2008 (Federal Register, Vol. 73, 

No. 64, pages 17897 to 17901). There are no further SIP requirements for the existing standard as 

long as the area continues to monitor attainment for the standard. San Antonio is the second most 

populated city in the State of Texas with about 1.4 million people and is located on the northwest 

edge of the Gulf Coastal Plain, and thus has a modified subtropical climate (U.S. Census 2013; 

NOAA 2014c). In the winter the area is influenced by a continental climate, with winds from the 

north and west, and a modified maritime climate, with south and southeast winds from the Gulf of 

Mexico. Elevation ranges from 550 to 1000 feet above sea level. Summer temperatures average in 

the 80s and winter temperatures average in the 50s. Precipitation ranges widely between months 

and years due to the city’s location between a semi-arid area to the west and a much wetter and 

more humid area to the east (NCDC 2014; NOAA 2014c). 
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In the region south of the Dallas-Fort Worth air basin to the Austin-Round Rock, and between the 

Austin-Round Rock air basin and San Antonio air basin area, sources including agricultural dust and 

soil disturbances are major contributors to air pollution. In the Austin-Round Rock air basin and San 

Antonio air basin the predominant contributors to air pollution are point sources including power 

plants and industrial facilities, and mobile emissions combined (both road and non-road) (TCEQ 

2014a). 

3.1.3 Southern Section: San Antonio to South Texas 

The Southern Section of the proposed project begins in San Antonio, as discussed above, and 

terminates in south Texas, potentially in Laredo, the Texas-Mexico border in the west, or Corpus 

Christi in the Rio Grande Valley region (Brownsville, Harlingen, and McAllen) in the east. 

From the San Antonio air basin, the project could travel southwest through the counties of Bexar, 

Medina, Frio, La Salle, and Dimmit to the Texas-Mexico border in Webb County, roughly 50 miles 

northwest of Laredo. Alternatively, it could also travel to the southeast from the San Antonio air 

basin through the counties of Bexar, Atascosa, Live Oak, and Jim Wells. The route would then split 

to Laredo in the west through Duval and Webb counties, to the Corpus Christi air basin in the east 

through Nueces County, and to the Rio Grande Valley region in the southeast through Brooks, 

Hidalgo, and Cameron counties. 

The western portion of southern Texas, is sparsely populated with the exception of Laredo having a 

population slightly over 248,000 people. The eastern portion of south Texas is also sparsely 

populated with the exception of the urban area of Corpus Christi having a population of just over 

300,000. The southernmost tip of Texas bordered by Mexico and the Gulf of Mexico is sparsely 

populated with the exception of Brownsville, Harlingen, and McAllen (U.S. Census 2013). The area 

is characterized by low rolling hills with hardwood scrub. The areas along the coast have a 

subtropical climate due to its proximity to the Gulf of Mexico; however, the location in a semi-arid 

region results in lower precipitation than other Gulf coast regions. Humidity is high throughout the 

year due to the Gulf. Most of the precipitation falls in May and September, and winter is the driest 

season. However, the hurricane season from June to November can alter the amount of rainfall 

significantly. August and September are the main hurricane months. Winter temperatures can be 

warm and summers can be hot and very humid, with an average of 93 percent humidity in the 

mornings (NCDC 2014). 

In the rural regions, outside of the San Antonio air basin and Corpus Christi air basin, the 

predominant contributors to air pollution are area sources including agricultural dust and soil 

disturbances. In the San Antonio air basin and Corpus Christi air basin, the predominant 

contributors to air pollution are point sources including power plants and industrial facilities, and 

mobile emissions combined (both road and non-road) (TCEQ 2014a). 
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3.2 Existing Conditions 

Table 3-1 summarizes the general climate, existing air quality, attainment status, and major 

emission sources for each of the regions in the Study Area. Of all these regions, only the Dallas-Fort 

Worth area is designated as nonattainment for ozone and portions of Collin County is 

nonattainment for lead (2008 standard) and is in maintenance for the 1978 lead standard. The 

Dallas-Fort Worth area is in attainment or unclassified for all other pollutants. Other regions of the 

study area are in attainment or unclassified for all pollutants. Specific details about the air quality 

plans and activities and the ambient air quality conditions of each region are included in the 

sections below. 

Table 3-1: General Climate and Background Air Quality Conditions 

Study 

Segment 

Air Basin 

(Region) 

Counties and 

Main Cities 

Attainment/ 

nonattainment a 

Weather / 

Topography 

Main Sources 

of Air 

Emissions 

Northern 

Section: 

Oklahoma 

City to 

Dallas-and 

Fort Worth 

Central 

Oklahoma 

Intrastate Air 

Quality Control 

Region 

Oklahoma City; 

Garvin, 

Murray, Carter, 

and Love 

Counties 

Oklahoma: 

Attainment for all 

criteria pollutants 

Frequent winds, 

long hot summers 

and shorter 

milder winters; b,c

mostly flat with 

rolling hills 

Power plants, 

industrial, and 

mobile 

sources j

Northern Texas Cooke County Attainment 

Central 

Section: 

Dallas andFort Worth 

to San 

Antonio 

Dallas-Fort 

Worth – 

Arlington Basin 

Dallas, Fort 

Worth, 

Arlington; 

Denton, 

Tarrant, 

Dallas, 

Johnson, Ellis, 

and Collins 

Counties 

Dallas-Fort WorthArlington Area: 

Nonattainment 8-

hour ozone 

Collins County: 

Nonattainment, 

lead (2008 

standard), 

Maintenance 

(1978 standard) 

Attainment/unclas

sified for other 

criteria pollutants 

Humid 

subtropical 

climate with hot 

summers; 

continental 

climate with 

generally mild 

winters; d

rolling hills 

Power plants, 

industrial, and 

mobile 

sources (onroad and offroad) i
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Study 

Segment 

Air Basin 

(Region) 

Counties and 

Main Cities 

Attainment/ 

nonattainment a 

Weather / 

Topography 

Main Sources 

of Air 

Emissions 

Austin-Round 

Rock 

Austin, San 

Antonio; Hill, 

McLennan, 

Falls Bell, 

Williamson, 

Travis, and 

Caldwell 

Counties 

Attainment: 

Unclassified for all 

criteria pollutants 

Humid 

subtropical 

climate with hot 

summers and 

relatively mild 

winters but with 

sudden cold 

fronts; e 

elevations range 

from 400 feet to 

1,000 feet above 

sea level 

Power plants, 

industrial, and 

mobile 

sources i

Southern 

Section: 

San 

Antonio to 

South 

Texas 

San Antonio Guadalupe 

and Bexar 

Counties 

Attainment/ 

unclassified for all 

criteria pollutants 

Humid 

subtropical 

climate with hot 

summers and 

relatively mild 

winters; elevation 

ranges from 550 

to 1,000 feet 

above sea level f

In rural areas, 

agricultural 

dust and soil 

disturbances; 

In other areas: 

power plants, 

industrial, and 

mobile 

sources (onroad and offroad) i

Southern 

Texas 

Laredo / Along 

the TexasMexico border; 

sparsely 

populated. g

Attainment/ 

unclassified for all 

criteria pollutants 

Semi-arid region 

results in lower 

precipitation than 

other Gulf Coast 

regions; low, 

rolling hills. 

In rural areas 

Agricultural 

dust and soil 

disturbances; 

In other areas 

Power plants, 

industrial, and 

mobile 

sources (onroad and offroad) i

Corpus Christi 

in the Rio 

Grande Valley 

Region 

Attainment/ 

unclassified 

Subtropical 

climate h
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Study 

Segment 

Air Basin 

(Region) 

Counties and 

Main Cities 

Attainment/ 

nonattainment a 

Weather / 

Topography 

Main Sources 

of Air 

Emissions 

a EPA (2016c). 

b OCS (2014). 

c U.S. Census (2013); OCS (2014). 

d NCDC (2014); NOAA (2014a). 

e U.S. Census (2013); NOAA (2014b). 

f

 NCDC (2014); NOAA (2014c). 

g U.S. Census (2013). 

h NCDC (2014). 

i. TCEQ (2014a). 

j. ODEQ (2013b) 

In the 2010 Regional Haze Implementation Plan, the Oklahoma DEQ estimates that by 2018 

emissions of SO2, NOX and PM10 will generally decrease due to MACT and BART programs involving 

point sources such as power plants while NH3, VOC and PM2.5 emissions are projected to increase 

due primarily to economic growth factors (ODEQ 2013c). In the 2014 Regional Haze SIP, TCEQ 

estimates that by 2018 statewide emissions of SO2 and PM2.5 will increase slightly while NOX and 

PM10 emissions are expected to decrease. Electric power industry emissions, a major source of SO2

in Texas was analyzed to show a continued downward trend of 99,870 tons over a 7-year period 

from 2005 to 2011 (TCEQ 2014b). 

GHG emissions are not limited to regional boundaries but are global. GHG emissions from 

transportation have been growing steadily in recent decades. In 2014, GHG emissions in the United 

States from transportation accounted for about 26 percent of total GHG emissions, making it the 

second largest contributor of US greenhouse gas emissions after the electricity section. GHG 

emissions from transportation have increased by 17 percent since 1990 (EPA 2016b). The majority 

of transportation sector GHG emissions result from fossil fuel combustion. CO2 is the largest 

component of these GHG emissions. 
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4.0 Impact Evaluation Methods 

Effects on air quality are classified by the type of pollutant, the area of effect, and the duration of 

effect. The type of potential regional and/or localized air quality effects and the impact evaluation 

approach of each type of effect are described in the following sections. 

4.1 Types of Effects and Evaluation Approach 

Several types of potential effects on air quality were considered for each alternative evaluated. The 

description of the effects, evaluation approach, and which contributing factors relate to the severity 

of the effect on air quality are discussed below. 

4.1.1 Short-term Construction Effects 

Construction effects on air quality are generally short term and are due to the emissions from 

construction equipment, fugitive dust from ground-level disturbances, on-site materials processing 

and handling such as concrete plants, and vehicle emissions from increases in local traffic 

congestion. The potential construction impacts on air quality are evaluated based on the intensity 

of the construction activities and duration of the construction of the Program and corresponding 

alternatives. The longer the construction period and the more non-road construction equipment 

used (such as cranes, bulldozers, heavy duty trucks, and concrete batch plants), the greater the 

potential for construction effects on air quality. 

4.1.2 Long-Term Regional Effects 

Long-term regional effects on air quality were evaluated based on both the direct and indirect 

emissions from operation of the Program. The proposed Program will affect air quality through 

several modes of transportation. These modes include travel between cities by on-road passenger 

vehicle travel and buses. It will also affect aircraft travel and electrical demands. To estimate the 

potential effect on regional emissions, results from regional transportation modeling were used to 

determine VMTs by mode type. The VMTs account for ridership projections and travel demand 

needs. Details of the assumptions that went into the air emission evaluation are provided in the 

following sections. The VMTs by mode type were used with source specific emission factors to 

determine the regional emissions by mode. Details of the assumptions used for each mode type 

are described in the subsequent sections. 

4.1.2.1 On-Road Vehicles 

An on-road vehicle emission analysis was conducted using average daily VMTs at average freeway 

speeds within the counties of the project area. Emission factors were estimated using EPA’s Motor 

Vehicle Emission Simulator (MOVES) model run in emission factor mode. The MOVES model 

provides emission factors in grams per mile, which are based on speed, vehicle mix, and analysis 

year for specific counties. Parameters were set to determine emission factors in each region of the 
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project area for the existing year 2013 and the project year 2035. Three counties were chosen to 

represent each region of the project, Canadian County, Oklahoma, for the Northern Section; Dallas 

County, Texas, for the Central Section; and Cameron County for the Southern Section. To determine 

the overall pollutant concentrations, the estimated VMTs were multiplied by the specific pollutant’s 

emission factors. The traffic model did not project changes in emissions for the intercity bus VMTs 

among the existing conditions, build alternatives, and No Build Alternative. Emissions for passenger 

vehicles are provided in Appendix A, Table A-1, and emissions for intercity buses are provided in 

Appendix A, Table A-2. 

4.1.2.2 Airport Emissions 

The FRA’s Emissions and Dispersion Modeling System (EDMS) was used to estimate airplane 

emissions. EDMS estimates the emissions generated from a specified number of landing and takeoff cycles. Average plane emissions were calculated based on the profile of the aircraft, assumed to 

be similar to a Boeing 737, series 300 passenger plane. In addition to air travel emissions from 

ground support equipment were included in this evaluation. The travel demand model values were 

used to determine the number of airplanes per day in each regional segment area. The existing 

travel demand modeling does not indicate that there would be a change in air emissions due to the 

proposed project. Therefore, the number of airplanes per day does not change between the 

existing, no build, or build scenarios. Emissions for airplanes in each region are provided in 

Appendix A, Table A-3. 

4.1.2.3 Power Generation Emissions 

Indirect effects on air quality are effects that are not generated directly from the project but are still 

a result of the proposed project. Indirect emissions included in this evaluation are those associated 

with increased electricity demand. The electrical demands due to propulsion of the electrical trains 

were calculated based on average engine size and the associated electrical demand. Average GHG 

emission factors for each kilowatt-hour were obtained from EPA’s Emissions & Generation 

Resource Integrated Database (eGRID) electrical generation data based on emission profiles from 

the Oklahoma and Texas electrical grids. The eGRID sub-region SPP South (SPSO) was used for the 

Northern Section, while the sub-region ERCOT ALL (ERCT) regional factors were used for the Central 

and Southern sections. Criteria pollutant emission factors were developed based on the annual 

electricity output from eGRID and the annual state wide emissions from combustion of power 

sources from EPA’s national emissions inventory database. Emissions associated with the potential 

increase in electrical demand were calculated for alternatives with electrical train options. While 

these emissions would not be located directly adjacent to the railway, they are accounted for in the 

regional emissions totals. Emissions for electric-powered locomotives are provided in Appendix A, 

Table A-4. 
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4.1.2.4 Diesel Locomotive Emissions 

Railroad activity releases emissions, primarily from diesel combustion during train operations. 

Emissions of NOx and primary PM2.5 from diesel combustion contribute to ambient concentrations 

of ozone and PM2.5, pollutants for which many states have areas out of attainment with the NAAQS. 

Diesel combustion also releases air toxics and GHGs, pollutants for which many states have 

established reduction programs. 

Emissions from diesel engine locomotives were calculated using emission factors published by EPA, 

Emission Factors for Locomotives (EPA 2009) and the train schedules developed in the traffic 

technical evaluation. Emissions from diesel locomotives are provided in Appendix A, Table A-5. 

4.1.3 Localized Effects 

Localized vehicle emissions of CO would occur at locations when a large amount of vehicles are 

idling, such as at congested intersections. During construction there may be additional traffic 

delays due to the increased need for construction crews and delivery of material. These delays 

would generally be short in duration. 

During operation, vehicles traveling to and from the stations or other rail facilities would have the 

potential to increase localized CO emissions at intersections or parking locations if such vehicle 

travel were to cause new congestion. In addition, localized PM and air toxic emissions would occur 

at locations with a substantial amount of diesel vehicle or diesel train travel/idling. 

A localized adverse effect would occur if the alternative would cause a localized air emissions 

increase that has the potential to cause violation of the NAAQS, cause or contribute to a substantial 

air toxic emission increase that exposes sensitive populations to a high level of air toxic 

concentrations, or result in a stationary source that could not be permitted by the local regulatory 

agency due to a local increase in air emissions. For this service-level analysis, there is insufficient 

project-specific data available to make a determination regarding potential for substantial local 

effects. Therefore, where an alternative would have a higher potential for localized vehicle 

emissions of CO, PM, or air toxics, a detailed project-level localized effects analysis is 

recommended. 

4.1.4 Greenhouse Gas Emissions 

GHG emissions from the Program would be due to fossil fuel combustion of vehicles, diesel trains, 

airplanes, and power plants that provides electricity to meet the Program’s power demand. 

Potential change in GHG emissions from implementation of the Program were calculated for the 

same sources and categories as identified above in Section 4.1.2, Long-term Regional Effects. 
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4.2 Intensity of Effects Criteria 

The air quality effects are characterized as negligible, moderate, or substantial as compared to the 

No Build Alternative. 

A substantial effect on air quality would have some or all of the following characteristics: 

 Short-Term Construction Effects: Construction emissions would be determined to have 

substantial adverse short-term effects if construction activities would generate air emissions in 

a quantity and location that would have the potential to cause or contribute to an exceedance of 

an ambient air quality standard or generate fugitive dust or other pollutants to a level that would 

be a nuisance. There are no beneficial short-term effects from construction for air quality. 

 Long-Term Regional Operational Effects: 

- Regional Adverse Effects: Regional adverse effects would be substantial if the net increase 

in emissions of criteria pollutants is greater than 100 tons per year between the No Build 

Alternative and the build alternative. 

- Regional Beneficial Effects: Substantial beneficial effects on air quality are based on a 

noticeable reduction in air emissions due to the alternative. Although a substantial reduction 

may not directly result in a change of attainment status for a region, it would cause or 

contribute to an overall measureable and continued improvement to the air quality in the 

region. The improvement could be due to a reduction of criteria pollutants, air toxics, or GHG 

emissions. A regional beneficial effect on GHG emissions would occur if the alternative is 

consistent with federal, state, or local GHG reduction strategies. 

 Localized Adverse Effects: A localized adverse effect would occur if the alternative would cause 

a localized air emissions increase that has the potential to cause violation of the NAAQS; cause 

or contribute to a substantial air toxic emission increase that exposes sensitive populations to a 

high level of air toxic concentrations; or result in a stationary source that could not be permitted 

by the local regulatory agency due to a local increase in air emissions. For this service-level 

analysis, there is insufficient project-specific data available to make a determination regarding 

potential for substantial local effects. Therefore, where an alternative would have a higher 

potential for localized vehicle emissions of CO, PM, or air toxics, a detailed project-level localized 

effects analysis is recommended. 

 GHG Effects: An individual project does not generate enough GHG emissions to significantly 

influence global climate change. Rather, global climate change is a cumulative impact. This 

means that a project may contribute to a potential impact through its incremental change in 

emissions when combined with the contributions of all other sources of GHG. Currently there 

are no applicable quantitative GHG emission thresholds to determine the level of GHG and 

climate change impacts from an individual project. For this analysis, substantial regional 

adverse effects would occur when the alternative or the Program design are inconsistent with 
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federal, state, and local emission reduction goals. A regional beneficial effect would occur if the 

alternative is consistent with the federal, state, or local GHG-reduction goals. 

A moderate effect would be noticeable, but overall the emissions and effects would be less than a 

substantial effect. Specifically, the effects would be moderate if the net increase in emissions from 

operations of criteria pollutants is less than 100 tons per year between the No Build Alternative and 

the build alternatives. A proportional reduction in short-term construction-related emissions and 

fugitive dust would result in a moderate effort. 

A negligible effect is one that would result in similar or limited emissions compared to the No Build 

Alternative and would result in no noticeable change. Construction emissions would be determined 

to have negligible short-term effects if construction activities generate air emissions in a quantity 

and location that would not have the potential to cause or contribute to any exceedance of an 

ambient air quality standard and would also not generate fugitive dust or other pollutants to a level 

that would be a nuisance. 

4.3 General Conformity 

For project areas located in nonattainment and maintenance areas under NAAQS, the project would 

be subject to the general conformity rule and required to demonstrate compliance with the 

conformity requirements. The EPA Final Conformity Rule requires that total direct and indirect 

emissions of nonattainment and maintenance criteria pollutants, including ozone precursors (VOC 

and NOx), be considered in determining conformity. If a federal action meets de minimis

requirements established in 40 CFR 93.153(b), detailed conformity analyses are not required. 

General conformity applicability analysis (e.g., to demonstrate that project emissions would be less 

than the general conformity de minimis levels) would be conducted at the project level for each 

project that is located in Dallas-Fort Worth nonattainment or maintenance areas. Further conformity 

determination will be required if the emissions exceed the de minimis levels for the nonattainment 

or maintenance pollutants. 
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5.0 Environmental Consequences 

5.1 Overview 

This sections discusses the air quality effects due to the implementation of the Program. Impacts 

were evaluated for the short-term construction emissions, long-term regional operational 

emissions, localized impacts of vehicle emissions of CO, PM, and air toxics, and GHG emissions. 

In general, alternatives located in a nonattainment or maintenance area would have a greater 

potential for effects on air quality due to the already degraded state of air quality. Additionally, 

alternatives that have higher concentrations of air pollutants located near areas of higher 

population have the potential to expose more people to air pollutions. Each type of service 

(conventional rail, higher-speed rail, and high-speed rail) has general characteristics that would 

have similar effects regardless of alternative. Construction effects were evaluated not on the type 

of service, but based on the potential size and scale of construction. The operational effects by type 

of service are summarized and the long-term regional effects are similar for all alternatives 

evaluated unless otherwise noted. 

5.1.1 Short-term Construction Effects 

The Program would involve construction of the rails and other facilities such as stations and 

maintenance yards that support the operation of the rail system. These construction activities can 

result in short-term increases in dust and equipment-related emissions in and around the 

construction site. Exhaust emissions during construction would be generated by fuel combustion in 

motor vehicles and construction equipment, and particulate emissions would result from soil 

disturbance, earthwork, and other construction activities. Construction vehicle activity and 

disruption of normal traffic flow may result in increased motor vehicle emissions within certain 

areas. 

Construction of the build alternatives would have the potential to cause temporary air quality 

impacts, and the extent of the impact would vary slightly based on alternative. In general, the 

degree of adverse construction effects is proportional to length of new rail proposed to be 

constructed, number of grade separations, number and size of new facilities, relationship of the 

alignment to populated areas, and the duration of construction at each site. The more non-road 

construction equipment used; the greater the potential for construction effects on air quality. 

Therefore, the alternatives with shorter route alignments, smaller right-of-way footprints, and/or 

using existing infrastructure and alignments would result in fewer effects on air quality from 

construction. Construction sites located farther away from populated areas would have less 

potential to cause air toxic effects on sensitive populations. Additionally, within the EIS Study Area, 

the Dallas and Fort Worth area is classified as a nonattainment area for ozone. Therefore, 

construction activities in the Dallas and Fort Worth area would have a greater potential effect on air 

quality than other regions due to the higher ambient background of ozone and ozone precursors. 
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Regardless of the differences in alternative service types (i.e., higher-speed, high-speed, or 

conventional), potential air quality impacts from each construction project would be short-term, 

occurring at a location only while construction work is in progress. Construction activities will 

comply with applicable federal, state, and local regulations and best management practices (BMPs) 

will be implemented to minimize emissions. 

5.1.2 Long-Term Regional Operational Effects 

Operation of the build alternatives would generally result in a long-term net benefit to air quality by 

reducing emissions of criteria pollutants, air toxics, and GHG. There are several factors which would 

contribute to the extent to which the operation of the alternative has a long-term effect on air 

quality. These include: the locomotive power source (diesel versus electric), operation of the 

stations and other supporting facilities, the forecasted ridership of the rail system and the 

subsequent vehicle and airplane emission change due to the shift of travel mode. 

Alternatives that use electricity powered trains such as high-speed rail would result in much lower 

direct effects on air quality due to a decrease in overall fuel consumption compared to alternatives 

that use diesel locomotives such as the conventional rail and higher-speed rail. Electric-powered 

trains would have lower regional emissions, fewer local incidences of increased pollutant 

concentrations due to train idling, and fewer potential health effects from diesel PM. 

While electric-powered trains would result in indirect emissions from power plants, these indirect 

emissions would be at a much lower levels compared to the diesel locomotive emissions. About 

50 percent of electric power production for the Texas and Oklahoma is from coal, with the 

remainder of production from the combustion of natural gas and renewable sources, which 

generate fewer emissions than the combustion of diesel (U.S. Energy Information Administration 

2014). 

Alternatives with higher ridership would have the potential to shift more passengers from driving to 

riding the trains, thus decreasing the regional VMT and the associated vehicle emissions. In 

addition, longer route segments would provide access to more locations and would likely have a 

greater reduction in regional VMT. Since the high-speed rail service type is projected to have greater 

ridership than higher-speed rail for the same alignment, it would result in a greater reduction of air 

emissions in the region due to the combined effects of using electric-powered trains and higher 

ridership. Therefore, compared to the higher-speed rail service type, the high-speed rail service 

types for the same alignment have a larger reduction in regional air pollutant emissions and a 

greater net benefit to air quality than shorter routes. 

Long-term regional effects of the build alternatives were evaluated based on the total direct and 

indirect emissions associated with the Program operation, Long-term operational emissions from 

trains, regional VMT changes, airplanes, and power generation are calculated for each Program 

alternative, except C4B Higher-Speed Rail and C4C Higher-Speed Rail. The traffic demand modeling 
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for C4B Higher-Speed Rail and C4C Higher-Speed Rail was not performed at the same levels as 

other alternatives, therefore, emissions of these two alternatives were not quantified. 

Total emissions of each alternative are summarized in Table 4-1. Detailed discussion of long-term 

regional effects of the No Build alternative and build alternatives are discussed in Section 5.2 

through Section 5.5. 

Table 5-1: Summary of Operational Regional Air Quality Emissions 

Evaluation Years VOC CO NOx SO2 PM10 PM2.5 CO2 

N4A – Conventional: Emissions Tons per year 

2013 256 7,271 2,257 11 66 45 619,797

2035 No Build Alternative 20 2,857 256 4 59 15 569,972

2035 Build Alternative 20 2,841 255 4 59 15 566,919

C4A HSR: Emissions Tons per year 

2013 261 7,096 2,312 12 67 45 647,748

2035 No Build Alternative 44 4,126 1,051 8 90 29 990,694

2035 Build Alternative 23 3,104 133 5 70 15 880,246

C4A HrSR- Diesel Emissions Tons per year 

2013 234 7,294 1,578 12 47 25 620,683

2035 No Build Alternative 40 4,028 827 7 88 27 938,132

2035 Build Alternative 29 3,543 357 6 79 19 771,182

C4B HSR: Emissions Tons per year 

2013 226 7,014 1,529 12 46 24 597,632

2035 No Build Alternative 41 4,042 938 7 88 28 957,194

2035 Build Alternative 22 3,090 132 5 69 15 901,358

C4C HSR: Emissions Tons per year 

2013 225 6972 1,521 12 46 24 594,172

2035 No Build Alternative 44 4,112 1,050 8 89 29 987,791

2035 Build Alternative 23 3137 134 5 70 15 936,978

S4 HrSR - Diesel: Emissions Tons per year 

2013 485 16,236 2,521 24 75 31 1,226,662

2035 No Build Alternative 83 12,945 442 16 261 57 2,408,974

2035 Build Alternative 86 13,049 599 17 262 60 2,449,934

S6 HrSR – Diesel: Emissions Tons per year 

2013 97 3,232 516 5 16 7 246,172

2035 No Build Alternative 8 1,307 47 2 27 6 246,083

2035 Build Alternative 9 1,296 102 2 26 6 253,037

S6 HSR: Emissions Tons per year 

2013 97 3,232 516 5 16 7 246,172
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Evaluation Years VOC CO NOx SO2 PM10 PM2.5 CO2 

2035 No Build Alternative 8 1,307 47 2 27 6 246,083

2035 Build Alternative 8 1,230 45 2 25 6 343,919

There was no projected change in air traffic or bus travel from 2013 to 2025 or as a reduction due to the build 

alternatives. 

The Northern and Central sections have existing rail travel that was assumed to grow similar to that of the build 

alternatives and is diesel fueled based on the existing infrastructure. The southern section does not have any rail 

except for that associated with the project alternatives. 

Traffic data provided by Steer Davies Gleave, March 1, 2016, version 2252703 – TOPRS Phase 3. 

HrSR = higher-speed rail; HSR = high-speed rail 

5.1.3 Localized Impacts 

It is anticipated that the Program build alternatives would reduce overall traffic congestion of the 

region by removing passenger vehicles from roadways. Because localized CO and PM emissions 

tend to occur at locations with large amount of vehicles idling, such as at congested intersections, 

the program would be beneficial to reduce localized vehicle emissions by relieving traffic 

congestions. 

While the conventional and potentially higher-speed service types could add new at-grade rail 

crossings that would increase localized vehicle emissions at those isolated locations, other service 

types such as high-speed rail would have grade separated crossing, therefore, would not increase 

localized vehicle emissions at these crossings. Traffic congestions and localized impacts of CO and 

PM may also occur near large rail stations on routes that passengers use to travel to and from the 

stations. 

Localized air toxic emissions from the Program operation would have the potential to exposure 

nearby population to air toxics such as diesel PM. Potential localized air toxic emissions associated 

the Program operation would be mostly from the diesel locomotives idling. However, localized air 

toxic emissions from diesel train travel are expected to be limited due to the limited number of 

diesel locomotive would idle at a particular location. Localized air toxic effects would be higher in 

urban or populated areas due to the exposure of sensitive receptors. Alternatives with alignments 

and facilities located mostly in rural areas, such as those in Southern Sections, would likely have 

lower potential to cause localized air toxic exposure then alternatives located in Central Sections 

that has dense populated areas. 

Electric trains idling would not emit air pollutants to increase local concentrations of pollutants near 

the alignment, nor would they increase the exposure of sensitive populations to toxic pollutants. 

Therefore, the high-speed rail alternatives would result in fewer local effects on air quality and air 

toxic exposure than the alternatives which would utilize diesel trains. 
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Increased travel speeds associated with the high-speed rail would have the potential to generate 

more fugitive dust compared to the operation of higher-speed rail. This would be minimized through 

the design and materials of the track as well as the grade separation requirement. 

As discussed above, the Program would be beneficial in reducing localized effects in some cases 

and would have adverse effects in other cases. Final conclusions of localized effects would be 

greatly depend on design details information on affected locations and the corresponding traffic 

data that are not available as part of this service-level evaluation. Therefore, localized effects of the 

Program would be evaluated at the project level when project specific information becomes 

available and are not further concluded in this study. 

5.1.4 General Conformity 

For alignments that are located in the Dallas and Fort Worth area that is designated as 

nonattainment for ozone, the Program would be subject to conformity requirements. A general 

conformity determination would be required during project level analysis if project construction and 

operation emissions would exceed the general conformity de minimis levels. Because project level 

information is not currently available, analysis related to general conformity will be performed 

during project-level analysis, and a conclusion is not made in this service level analysis. 

5.2 No Build Alternative 

The No Build Alternative, as described in Chapter 2 (Section 2.2) and the introduction to Chapter 3, 

of the Draft EIS, is used as the baseline to evaluate the air quality effects of the build alternatives. 

The No Build Alternative would not implement the Program of rail improvements associated with 

this service-level evaluation and would not meet the purpose and need of the Program. The No 

Build Alternative would not require any construction. Therefore, there are no short term effects on 

air quality from the No Build Alternative. 

Existing air quality, compared to air quality in 2035 without the project, would be affected by two 

key factors: regional growth and air quality regulatory actions. Regional growth, such as increased 

residential development and density, along with additional industry, results in more and greater 

sources of air emissions. These increases in air emissions are offset by transportation projects 

which generally reduce traffic congestion, thus minimizing local effects for emissions, as well as 

vehicle regulatory programs that control the level of emissions from on-road and non-road vehicles. 

Due to the Texas Motor Vehicle Fuel Programs, the TERP, and the Vehicle I/M Program, it is 

expected that pollutant burdens for VOC, CO, NOx, and PM would continue to decrease from the 

current conditions to 2035 (TCEQ 2014c). The Fuel Programs such as the Texas Low Emission 

Diesel Fuel Program initially implemented in 2005 will continue to reduce emissions in the region 

(TCEQ 2014d). Emissions will continue to be reduced from of the TERP and the I/M Programs due 

to the phasing of implementation dates (TCEQ 2014c). Additionally, under the No Build Alternative, 
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several roadway and mass transit projects, as discussed in the Alternative section, are designed to 

alleviate congestion through the entire region. The effect of the federal mobile vehicle emission 

reduction programs is included in Motor Vehicle Emission Simulator emission factors and reflected 

in the 2035 alternative emission evaluations. Regional emission reduction programs would reduce 

the future emission of the project area. The No Build Alternative would not require construction and 

operation of any component of the Program. 

5.3 Northern Section: Oklahoma City to Dallas and Fort Worth 

5.3.1 Alternative N4A Conventional Rail 

5.3.1.1 Construction 

Alternative N4A would primarily use the existing rail infrastructure, which would require minimal 

construction activities to implement this alternative. Due to the limited construction emissions 

associated with these minimal construction activities, short-term effects on air quality would be 

negligible for Alternative N4A. 

5.3.1.2 Operation 

Relative to the No Build Alternative, Alternative N4A would slightly decrease the amount of travel by 

personal vehicles, which are typically gasoline fueled. Therefore, Alternative N4A would result in 

slightly lower regional emissions from personal vehicles compared to the No Build Alternative. 

Alternative N4A would use Tier 4 or similar diesel locomotive engines. As shown in Table 4-1, there 

would be a negligible reduction (less than 1 percent) in CO, NOx, and CO2 pollutants relative to the 

No Build Alternative. Because regional criteria pollutants and GHG emissions from Alternative N4A 

would be similar or slightly lower relative to the No Build Alternative, the overall benefit in regional 

air quality would be negligible 

5.4 Central Section: Dallas and Fort Worth to San Antonio 

The construction of any of the Central Section alternatives would be a major infrastructure project 

and would occur in an area that is currently designated as serious nonattainment for ozone. Even 

with mitigation, all Central Section alternatives under consideration would likely result in 

substantial short term effects on air quality during construction. 

5.4.1 Alternative C4A Higher-Speed Rail 

5.4.1.1 Construction 

Construction of Alternative C4A Higher-Speed Rail would be a major infrastructure project and 

would occur in an area that is currently designated as nonattainment for ozone. It is anticipated 

that the construction of C4A Higher-Speed Rail would generate substantial short-term regional air 

quality emissions. 
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5.4.1.2 Operation 

Operation of the alternative would reduce criteria pollutants and GHG emissions compared to No 

Build Alternative, as shown in Table 4-1. Emissions of criteria pollutants with this alternative would 

be reduced by 10 to 57 percent compared to No Build Alternative, with NOx having the greatest 

reduction, attributed mostly to the reduced travel time of the higher-speed rail service types and 

their resulting reduced fuel usage. 

GHG emissions are generated from the combustion of fossil fuels. As shown in Table 4-1, the 

regional reduction in emissions would be approximately 167,000 tons per year, or 18 percent for 

CO2 compared to the No Build Alternative. Emission reductions of GHG are mainly due to the 

reduced travel time and resulting reduced fuel usage. 

Because the air pollution emissions would be greatly reduced, Alternative C4A Higher-Speed Rail 

would have substantial regional benefits. 

5.4.2 Alternative C4A High-Speed Rail 

5.4.2.1 Construction 

Alternative C4A High-Speed Rail would result in higher short-term construction emissions compared 

the higher-speed rail service type because it would require more grade-separated segments, a 

larger construction footprint, and more mobilization effort due to the high-speed rail track and 

station design requirements. The scale of the construction project would likely result in a 

substantial effect on regional air quality. 

5.4.2.2 Operation 

Operation of Alternative C4A High-Speed Rail would have greater regional beneficial impacts on air 

quality due to the higher ridership (reducing reliance on vehicles) and use of electric trains. As 

shown in Table 4-1, emissions of criteria pollutants would be reduced by 25 to 87 percent 

compared to No Build Alternative, with NOx having the highest reduction, attributed mostly to the 

use electric-powered trains. 

The regional reduction in emissions would be approximately 110,000 tons per year, or 11 percent, 

for CO2 compared to the No Build Alternative, mostly due to the use of electric-powered trains and 

the passenger vehicle emission reduction when people switch from driving to riding the trains. 

Because the air pollution emissions would be greatly reduced, Alternative C4A High-Speed Rail 

would have substantial long-term regional benefits. 
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5.4.3 Alternative C4B Higher-Speed Rail 

5.4.3.1 Construction 

Similar to Alternative C4A Higher-Speed Rail, construction of Alternative C4B Higher-Speed Rail 

would also represent a major infrastructure project in an area that is currently designated as 

nonattainment for ozone. However, as the shortest rail alignment with the smallest right-of-way, 

Alternative C4B Higher-Speed Rail is expected to result in fewer short-term impacts effects on air 

quality from construction than Alternative C4A Higher-Speed Rail would. There is a potential for 

substantial short-term effects on air quality. 

5.4.3.2 Operation 

For this service-level analysis, the travel demand modeling for Alternative C4B Higher-Speed Rail 

was not conducted to the same level of detail as Alternative C4A Higher-Speed Rail, but instead 

relied upon a proportional relationship based on full travel demand modeling conducted for 

Alternatives C4A High-Speed Rail and C4A Higher-Speed Rail. This appropriate level of detail 

applied for Alternative C4B Higher-Speed Rail is supported by a linear proportional adjustment in 

ridership and demand, which is based on the relationship between Alternatives C4A High-Speed 

Rail and C4A Higher-Speed Rail, thereby producing reasonably accurate estimates for Alternative 

C4B Higher-Speed Rail. 

The higher-speed rail service type would use diesel train during operation. However, the overall 

emissions of each criteria pollutant and GHG are expected to decrease compared to the No Build, 

similar to C4A Higher-Speed Rail, but at a reduced level due to the shorter alignment and 

subsequently less vehicles being removed from road. The air pollution emissions would be reduced, 

similar to Alternative C4A Higher-Speed Rail; the corresponding reductions, taking into account the 

shorter alignment, would have moderate regional benefits. 

5.4.4 Alternative C4B High-Speed Rail 

5.4.4.1 Construction 

Alternative C4B High-Speed Rail would have design of rail tracks, facilities, and grade-separated 

crossings similar to Alternative C4A High-Speed Rail but would have a shorter rail alignment and 

smaller right-of-way. Air quality effects from construction of Alternative C4B High-Speed Rail would 

likely be fewer than those associated with Alternative C4A High-Speed Rail. Alternative C4B HighSpeed Rail would likely have short-term moderate effects on air quality. 

5.4.4.2 Operation 

Alternative C4B High-Speed Rail would have a shorter alignment than Alternative C4A High-Speed 

Rail and as a result VMT reductions would be smaller. Operation of Alternative C4B High-Speed Rail 
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would result in similar but slightly fewer benefits than Alternative C4A High-Speed Rail, as 

compared to the No Build Alternative. As shown in Table 4-1, emissions of criteria pollutants would 

be reduced by 22 to 86 percent compared to No Build Alternative, with NOx having the highest 

reduction, attributed mostly to the use electric-powered trains. The regional reduction in CO2

emissions would be approximately 56,000 tons per year, or 18 percent, compared to the No Build 

Alternative. 

Because the air pollution emissions would be greatly reduced, Alternative C4A High-Speed Rail 

would have substantial long-term regional benefits 

5.4.5 Alternative C4C Higher-Speed Rail 

5.4.5.1 Construction 

Air quality effects from construction of Alternative C4C Higher-Speed Rail would be similar to but 

greater than those identified for Alternative C4A Higher-Speed Rail due to the longer alignment for 

the C4C alternative. Alternative C4C Higher-Speed Rail would likely have substantial short-term 

effects on air quality. 

5.4.5.2 Operation 

For this service-level analysis, the travel demand modeling for Alternative C4C Higher-Speed Rail 

was not conducted to the same level of detail as for C4A Higher-Speed Rail, but instead relied upon 

a proportional relationship based on full travel demand modeling conducted for the C4A HighSpeed Rail and C4A Higher-Speed Rail alternatives. This appropriate level of detail applied for 

Alternative C4C Higher-Speed Rail is supported by a linear proportional adjustment in ridership and 

demand, which is based on the relationship between the C4A High-Speed Rail and C4A HigherSpeed Rail alternatives, thereby producing reasonably accurate estimates for Alternative C4C 

Higher-Speed Rail. 

Air quality effects from the operation of Alternative C4C Higher-Speed Rail would be similar to those 

discussed for Alternative C4A Higher-Speed Rail. Similar to C4A Higher-Speed Rail, but with a 

slightly increased level due to the longer alignment and more vehicles removed from the road, the 

air pollution emissions would be reduced and the corresponding reductions, taking into account the 

longer alignment, would have substantial regional benefits. 

5.4.6 Alternative C4C High-Speed Rail 

5.4.6.1 Construction 

Construction emissions of Alternative C4C High-Speed Rail would be higher than Alternative C4C 

Higher-Speed Rail due to the construction of grade-separated crossing. Alternative C4C High-Speed 

Rail would likely to have substantial short-term effects on air quality. 
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5.4.6.2 Operation 

Operation of Alternative C4C High-Speed Rail would result in similar but slightly fewer benefits than 

Alternative C4A High-Speed Rail, as compared to the No Build Alternative. As shown in Table 4-1, 

emissions of criteria pollutants would be reduced by 21 to 87 percent compared to No Build 

Alternative, with NOx having the highest reduction, attributed mostly to the use electric-powered 

trains. The regional reduction in CO2 emissions would be approximately 51,000 tons per year, or 

5 percent compared to the No Build Alternative. 

Because the air pollution emissions would be greatly reduced, Alternative C4C High-Speed Rail 

would have substantial long-term regional benefits. 

5.5 Southern Section: San Antonio to South Texas 

5.5.1 Alternative S4 Higher-Speed Rail 

5.5.1.1 Construction 

Construction of Alternative S4 Higher-Speed Rail would be a major infrastructure project. While the 

area is in attainment for ozone there is active management of ozone precursors in accordance with 

the Ozone Flex Plan (TCEQ 2007). Alternative S4 Higher-Speed Rail would be located in a mostly 

rural area and the station capacity is expected to be less than half that of the stations associated 

with the Central Section Alternatives. However, there is minimal existing rail infrastructure in the 

Southern Section, as shown in Section 3.20, Transportation, in the Draft EIS, which indicates there 

would be no existing or future passenger rail service in the area without the Program. Therefore, the 

major infrastructure construction required for this alternative would result in a substantial shortterm effect on air quality. 

5.5.1.2 Operation 

The regional emissions for Alternative S4 Higher-Speed Rail compared to the No Build Alternative 

are included in Table 4-1. Alternative S4 Higher-Speed Rail is expected to have an increase in 

criteria pollutants and GHG emissions compared to the No Build Alternative. This is because, 

although there would be a reduction in personnel VMT, the traffic modeling evaluation projected no 

change in bus or air miles traveled, and there is no future rail travel included in the No Build 

Alternative. Therefore, while Alternative S4 Higher-Speed Rail would provide additional modes of 

transport in the region the use of diesel-powered trains would increase emissions from Alternative 

S4 Higher-Speed Rail compared to the No Build Alternative for all pollutants evaluated. For NOx and 

CO, the increase is estimated to be approximately 157 and 104 tons per year, respectively. The CO2

emissions increase would be approximately 41,000 tons per year, or 2 percent, compared to the 

No Build Alternative. The increase in other pollutants would be negligible. 
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Because the emission increases associated with Alternative S4 Higher-Speed Rail would be greater 

than 100 tons per year for CO and NOx, it would have substantial regional adverse effects during 

operation. 

5.5.2 Alternative S6 Higher-Speed Rail 

5.5.2.1 Construction 

The alignment length of Alternative S6 Higher-Speed Rail is approximately one third the length of 

the S4 Higher-Speed Rail and S6 High-Speed Rail alternative alignments. Therefore, Alternative S6 

Higher-Speed Rail would have lower construction emissions than S4 Higher-Speed Rail and S6 

High-Speed Rail. Construction of Alternative S6 Higher-Speed Rail would likely result in moderate 

effects on air quality. 

5.5.2.2 Operation 

While Alternative S4 Higher-Speed Rail has a much longer alignment than S6 Higher-Speed Rail 

and is projected to have a lower level of ridership than Alternative S6 Higher-Speed Rail, there 

would be a proportionally greater reduction in regional VMT with Alternative S6 Higher-Speed Rail 

compared to S4 Higher-Speed Rail. As shown in Table 4-1, Alternative S6 Higher-Speed Rail would 

have a negligible reduction in emissions of PM and CO compared to the No Build Alternative. NOx

would increase by approximately 55 tons per year, and GHG would increase by 7,000 tons per year. 

Increases of NOx and GHG emissions are mostly due to the use of diesel-powered trains for 

Alternative S6 Higher-Speed Rail and the extremely low baseline emissions of the No Build 

Alternative. Because the alternative would cause criteria pollution emissions less than 100 tons per 

year, it would have moderate adverse effect on air quality during operation. 

5.5.3 Alternative S6 High-Speed Rail 

5.5.3.1 Construction 

Construction of Alternative S6 High-Speed Rail would have potential for higher short-term air quality 

effects than Alternative S6 Higher-Speed Rail due to the increased construction footprint and 

elevated structures required. Construction of Alternative S6 High-Speed Rail would likely result in 

short-term substantial effects on air quality. 

5.5.3.2 Operation 

Operation of the Alternative S6 High-Speed Rail would have greater beneficial effects than 

Alternative S6 Higher-Speed Rail due to the use of electric-powered trains. Although the high-speed 

rail service type would result in increases in emissions from power production, the associated 

indirect increase in emissions from power generation would be lower than emissions associated 

with diesel locomotives in Alternative S6 Higher-Speed Rail. These criteria and GHG emissions 
5.0 Environmental Consequences 

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would not be local and would be distributed throughout the state’s existing power supply sources, 

which are required to operate within their permit limits. The permits are issued on the basis that 

operation of the power plants will not result in an exceedance of an ambient air quality standard. 

The reduction in regional emissions associated with Alternative S6 High-Speed Rail would be 

negligible to moderate, or less than 7 percent, compared to No Build Alternative, for the pollutants 

evaluated except for CO2. There would be an increase in CO2 emissions due to the indirection 

emissions from power generation. Although there is projected to be an increase in GHG emissions 

for this alternative, it is primarily due to the addition of a transportation mode that did not 

previously exist in the region. Alternative S6 High-Speed Rail would be consistent with long-term 

federal and state goals to reduce the reliance on fossil fuels for new transportation alternatives 

because it would use electricity rather than direct combustion of diesel. 

Due to the minimal emission reduction of criteria pollutant, Alternative S6 High-Speed Rail would 

have negligible long-term regional benefits. 
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6.0 Potential Mitigation Strategies 

6.1 Construction Phase 

Temporary, short-term emissions increases associated with construction activities, and potential 

localized air pollution increases associated with traffic near proposed stations would be 

substantially reduced by the application of mitigation strategies and design practices. Potential 

emission reduction measures include, but are not limited to: 

 Use of low-emissions vehicles during construction, and use of newer and well-maintained 

equipment. 

 Effects from concrete and asphalt batch plants would be limited by placing these facilities 

farther from sensitive populations, such as schools, hospitals, and residences, to the extent 

possible. 

 Potential fugitive dust effects would be mitigated through best management practices such as 

water sprays during demolition; wetting, paving, or landscaping exposed earth areas; covering 

dust-producing materials during transport; limiting dust-producing construction activities during 

high wind conditions; and providing street sweeping and tire washes for trucks leaving the site. 

 Traffic congestion emissions can be reduced using site-specific traffic management plans; 

temporary signage and other traffic controls; designated staging areas, worker parking lots (with 

shuttle bus service if necessary), and truck routes; and prohibition of construction vehicle travel 

during peak traffic periods. 

Localized air pollutant increases associated with traffic near construction sites would be addressed 

by mitigation strategies discussed in Section 3.20, Transportation, in the Draft EIS, as well as 

implementing enhanced accessibility and signal design practices. 

6.2 Operational Phase 

Avoidance and minimization of effects at the project-level would be incorporated when feasible. If 

effects cannot be avoided or minimized, mitigation strategies would be implemented. Strategies for 

managing emissions from diesel trains could addressed by using Tier 4 locomotive engines, and 

implementing additional measures to reduce diesel locomotive idling times. Locating the tracks, 

stations, and other supporting facilities away from populated areas and sensitive receptors would 

minimize and reduce the potential exposure to air toxics from diesel combustion. 

 
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7.0 Subsequent Analysis 

7.1 Construction and Operation Emissions 

A detailed quantification of construction emissions based on the proposed segment and station 

construction will be conducted during project-level analysis. Project operation analysis will include 

emissions from operating the trains and stations of the alternatives and will include regional 

changes in emissions due to mode change. Based on the refined segment options, a detailed 

evaluation of the potential changes in VMT for all modes affected, including personal vehicles, 

airplanes, buses, and conventional train, will be included in subsequent analysis. The evaluation 

will also include the quantification of both direct and indirect air emissions during operation. 

7.2 Localized Impacts 

Localized impacts of CO, PM, and air toxics during operation will be performed during project-level 

analysis when project-specific information is available and will only be for alternative operations 

that are determined to have potential to increase localized emissions substantially. If a quantitative 

modeling analysis is triggered, air dispersion modeling of CO or PM will be conducted for locations 

that would have the potential to cause an exceedance of NAAQS, even with mitigation. 

7.3 General Conformity 

For alternatives located in the Dallas and Fort Worth area that is designated as nonattainment or 

maintenance for ozone, construction and operation emission evaluations will be performed and 

compared to the general conformity de minimis levels to demonstrate compliance with general 

conformity requirements. A general conformity evaluation is not required for projects located in 

attainment areas. 

7.4 Greenhouse Gases and Climate Change 

GHG emissions and the associated climate change impacts due to project emissions will be 

analyzed for the alternatives. GHG emissions from project operation in the study area will be 

quantified. In addition, a qualitative discussion of project adaptation to the effects of climate 

change will be included in the project-level analysis. 
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8.0 References 

Association of Central Oklahoma Governments (ACOG). 2012. Encompass 2035 Plan Report, 

Oklahoma City Area Regional Transportation Study. May 2012. Available at 

http://www.acogok.org/long-range-transportation-planning. 

Council on Environmental Quality (CEQ). 2014. Guidance on Considering Climate Change in NEPA 

Reviews and Conducting Programmatic NEPA Reviews. Available at 

https://www.whitehouse.gov/sites/default/files/docs/nepa_revised_draft_ghg_guidance_s

earchable.pdf. 

National Climatic Data Center (NCDC). 2014. Texas Climate Descriptions. Available at 

http://web2.airmail.net/danb1/texas_climate_descriptions.htm. Accessed August 2014. 

National Oceanic and Atmospheric Administration (NOAA). 2014a. Dallas/Fort Worth Climate 

Overview. National Weather Service Weather Forecast Office. Available at 

http://www.srh.noaa.gov/fwd/?n=dnarrative. Accessed August 2014. 

National Oceanic and Atmospheric Administration (NOAA). 2014b. Austin Climate Summary. 

National Weather Service Weather Forecast Office, Local South Central Texas Climate 

Information. Available at http://www.srh.noaa.gov/images/ewx/climate/ausclisum.pdf. 

Accessed August 2014. 

National Oceanic and Atmospheric Administration (NOAA). 2014c. San Antonio Climate Summary. 

National Weather Service Weather Forecast Office, Local South Central Texas Climate 

Information. Available at http://www.srh.noaa.gov/images/ewx/climate/satclisum.pdf. 

Accessed August 2014. 

Oklahoma Climatological Survey (OCS). 2014. Climate of Oklahoma. Available at 

http://climate.ok.gov/index.php/site/page/climate_of_oklahoma. Accessed August 2014. 

Oklahoma Department of Environmental Quality (ODEQ). 2013a. National Ambient Air Quality 

Standards (NAAQS). Updated October 9, 2013. Available at 

http://www.deq.state.ok.us/aqdnew/monitoring/naaqs.htm. Accessed August 2014. 

Oklahoma Department of Environmental Quality (ODEQ). 2013b. Oklahoma Air Quality Rules and 

Planning, Regional Haze Planning. Updated June 19, 2013. Available at 

http://www.deq.state.ok.us/aqdnew/RulesAndPlanning/Regional_Haze/index.htm. 

Accessed August 2014. 

Oklahoma Department of Environmental Quality (ODEQ). 2013c. Regional Haze Implementation Plan 

Revision. June 14, 2013. Available at 

http://www.deq.state.ok.us/AQDnew/rulesandplanning/Regional_Haze_rev2013/Final%20R

egional%20Haze%20SIP%20Revision%20(PSO)%20%206-14-13.pdf. Accessed August 2014. 
8.0 References 

Texas-Oklahoma Passenger Rail Study July 2016 

Air Quality Technical Study 8-2 

TR0411161129SDA

Oklahoma Department of Environmental Quality (ODEQ). 2014. Oklahoma Air Quality Rules and 

Planning, Oklahoma Infrastructure SIPs. August 12, 2014. Available at 

http://www.deq.state.ok.us/AQDnew/rulesandplanning/Infrastructure_index.htm. Accessed 

August 2014. 

Texas Commission on Environmental Quality (TCEQ). 2007. Corpus Christi Eight-Hour Ozone Flex 

Plan Memorandum of Agreement. 2007-008-MIR-NR. Available at 

http://www.tceq.texas.gov/airquality/sip/cc/cc-latest-ozone. Accessed August 1, 2014. 

Texas Commission on Environmental Quality (TCEQ). 2013a. Letter to EPA, Region 6 regarding 

recommendation for designation of areas in Texas with regard to the 2012 primary PM2.5

NAAQS. November 26, 2013. Available at 

http://www.tceq.texas.gov/assets/public/implementation/air/sip/pm25/Texas_PM_Design

ations_Recommendation.pdf. 

Texas Commission on Environmental Quality (TCEQ). 2013b. Dallas-Fort Worth: Current Attainment 

Status. Updated December 4, 2013. Available at 

http://www.tceq.texas.gov/airquality/sip/dfw/dfw-status. Accessed August 2014. 

Texas Commission on Environmental Quality (TCEQ). 2014a. Texas State Implementation Plan. 

Available at http://www.tceq.texas.gov/airquality/sip. Accessed August 2014. 

Texas Commission on Environmental Quality (TCEQ). 2014b. Five-Year Regional Haze Progress 

Report. Revisions to the State of Texas Air Quality Implementation Plan Concerning Regional 

Haze. Adopted February 26, 2014. Available at 

https://www.tceq.texas.gov/assets/public/implementation/air/sip/haze/13012SIP_ado. 

pdf. Accessed August 6, 2014. 

Texas Commission on Environmental Quality (TCEQ). 2014c. Vehicle Inspection and Maintenance 

(I/M) Program. Updated February 14, 2014. Available at 

https://www.tceq.texas.gov/airquality/mobilesource/im.html. Accessed August 8, 2014. 

Texas Commission on Environmental Quality (TCEQ). 2014d. Controlling On-Road Mobile Source 

Vehicle Emissions. Updated February 27, 2014. Available at 

http://www.tceq.texas.gov/airquality/mobilesource/mobile_source.html. Accessed August 

8, 2014. 

Texas Commission on Environmental Quality (TCEQ). 2014e. Emissions Inventory (EI) SIP Revision 

for the 2008 Eight-Hour Ozone Standard for the Houston-Galveston-Brazoria (HGB) and 

Dallas-Fort Worth (DFW) Areas. Updated July 2, 2014. 

https://www.tceq.texas.gov/airquality/sip/criteria-pollutants/sip-ozone. Accessed August 

2014. 
8.0 References 

Texas-Oklahoma Passenger Rail Study July 2016 

Air Quality Technical Study 8-3 

TR0411161129SDA

Texas Department of Transportation (TxDOT). 2014. Texas-Oklahoma Passenger Rail Study Route 

Alternatives Analysis. June. 

Texas Department of Transportation (TxDOT). 2015. Best Practice: Climate Change and 

Greenhouse Gas Emission Impact Statements. September 2015. 

U.S. Census Bureau (U.S. Census). 2013. State and County QuickFacts. Available at 

http://quickfacts.census.gov/qfd/index.html. Accessed August 2014. 

U.S. Department of Transportation (USDOT). 2010. Transportation’s Role in Reducing U.S. 

Greenhouse Gas Emissions. Volume 1: Synthesis Report. Report to Congress. April 2010. 

Available at http://ntl.bts.gov/lib/32000/32700/32779/DOT_Climate_Change_Report_-

_April_2010_-_Volume_1_and_2.pdf.

U.S. Energy Information Administration. 2014. Texas State Profile and Energy Estimates. Updated 

March 27, 2014. Available at http://www.eia.gov/state/?sid=TX. Accessed August 1, 2014. 

U.S. Environmental Protection Agency (EPA). 2008. 8 Hour Ozone Flex Program, Austin-Round Rock 

Metropolitan Statistical Area. Available at 

http://www.tceq.texas.gov/assets/public/implementation/air/sip/austin/AustinRoundRock8-HourOzoneFlexFinal.pdf. April 2008.

U.S. Environmental Protection Agency (EPA). 2009. USEPA Office of Transportation and Air Quality: 

Emission Factors for Locomotives (EPA-420-F-09-025). April 2009. 

U.S. Environmental Protection Agency (EPA). 2013. Ozone Advance Program. May 31, 2013. 

https://www.epa.gov/advance. 

U.S. Environmental Protection Agency (EPA). 2014. Endangerment and Cause or Contribute 

Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act. Available at 

http://www.epa.gov/climatechange/endangerment/. Accessed August 2014. 

U.S. Environmental Protection Agency (EPA). 2016a. NAAQS Table. Available at 

https://www.epa.gov/criteria-air-pollutants/naaqs-table. Accessed June 2016. 

U.S. Environmental Protection Agency (EPA). 2016b. Sources of Greenhouse Gas Emissions: 

Transportation Sector Emissions. Available at 

https://www3.epa.gov/climatechange/ghgemissions/sources/transportation.html. 

U.S. Environmental Protection Agency (EPA). 2016c. The Green Book Nonattainment Areas for 

Criteria Pollutants. Available at https://www3.epa.gov/airquality/greenbook/. Accessed 

June 2016. 


This report was written on behalf of the Texas Department of Transportation by 

www.ch2m.com 
Appendix A 

Emission Calculations 

Summary Tables

VOC CO NOx SO2 PM10 PM2.5 CO2

Auto 206.38                 7,078.95        1,201.45              10.76              37.77              17.45          545,734.47

Bus 0.48                              2.20                9.46                0.01                0.47                0.39              1,343.80

Airplane 0.02                              0.18                0.06                0.01                0.00                0.00                    19.03

Rail ‐ Electric 0.05                              0.26                0.52                0.32                0.04                0.03      1,126,794.14

Rail ‐ Diesel 49.10                       189.44        1,045.95                0.67              27.75              26.92            72,699.31

Total         255.97        7,270.76        2,256.92              11.45              65.99              44.76          619,796.61

Auto 209.04                 6,890.87        1,208.80              11.18              36.12              15.43               566,737

Bus 2.87                            13.09              55.90                0.07                2.78                2.35                    8,030

Airplane 0.24                              2.61                0.85                0.12                0.02                0.02                        281

Rail ‐ Electric 0.01                              0.16                0.15                0.24                0.02                0.01            1,211,577

Rail ‐ Diesel 49.10                       189.44        1,045.95                0.67              27.75              26.92            72,699.31

Auto 219.41                 7,232.50        1,268.73              11.73              37.91              16.19          594,834.55

Bus 2.87                            13.09              55.90                0.07                2.78                2.35              8,030.42

Airplane 0.24                              2.61                0.85                0.12                0.02                0.02                 280.65

Rail ‐ Electric 0.01                              0.16                0.15                0.24                0.02                0.01      1,211,576.68

Rail ‐ Diesel 11.84                         45.70            252.31                0.16                6.69                6.49            17,537.12

Auto 210.91                 6,952.24        1,219.57              11.28              36.44              15.57          571,784.19

Bus 2.87                            13.09              55.90                0.07                2.78                2.35              8,030.42

Airplane 0.24                              2.61                0.85                0.12                0.02                0.02                 280.65

Rail ‐ Electric 0.01                              0.16                0.15                0.24                0.02                0.01      1,211,576.68

Rail ‐ Diesel 11.84                         45.70            252.31                0.16                6.69                6.49            17,537.12

Auto 209.63                 6,910.16        1,212.19              11.21              36.22              15.47          568,323.79

Bus 2.87                            13.09              55.90                0.07                2.78                2.35              8,030.42

Airplane 0.24                              2.61                0.85                0.12                0.02                0.02                 280.65

Rail ‐ Electric 0.01                              0.16                0.15                0.24                0.02                0.01      1,211,576.68

Rail ‐ Diesel 11.84                         45.70            252.31                0.16                6.69                6.49            17,537.12

C4Ahsr 1         261.25        7,096.01        2,311.51              12.04              66.67              44.71          647,747.75

C4Ah ‐ Electric 1         222.54        7,248.36        1,325.64              12.16              40.73              18.57      1,814,722.30

CAAh‐Diesel 1         234.37        7,293.90        1,577.80              12.09              47.41              25.05          620,682.73

C4Bhsr 1         225.86        7,013.63        1,528.64              11.63              45.94              24.43          597,632.38

C4Chsr 1         224.59        6,971.56        1,521.26              11.56              45.72              24.33          594,171.97

Auto 481.53               16,222.32        2,465.25              24.02              71.79              28.03      1,218,125.96

Bus 3.05                            13.90              56.07                0.07                2.95                2.49              8,535.96

Airplane                 ‐ ‐                   ‐                   ‐                   ‐                   ‐                   ‐                         

Rail ‐ Electric                 ‐ ‐                   ‐                   ‐                   ‐                   ‐                   ‐                         

Rail ‐ Diesel                 ‐ ‐                   ‐                   ‐                   ‐                   ‐                   ‐                         

Auto 95.75                   3,225.82            490.22                4.78              14.27                5.57          242,225.17

Bus 1.41                              6.43              25.92                0.03                1.36                1.15              3,946.65

Airplane                 ‐ ‐                   ‐                   ‐                   ‐                   ‐                   ‐                         

Rail ‐ Electric                 ‐ ‐                   ‐                   ‐                   ‐                   ‐                   ‐                         

Rail ‐ Diesel                 ‐ ‐                   ‐                   ‐                   ‐                   ‐                   ‐                         

Auto 95.75                   3,225.82            490.22                4.78              14.27                5.57          242,225.17

Bus 1.41                              6.43              25.92                0.03                1.36                1.15              3,946.65

Airplane                 ‐ ‐                   ‐                   ‐                   ‐                   ‐                   ‐                         

Rail ‐ Electric                 ‐ ‐                   ‐                   ‐                   ‐                   ‐                   ‐                         

Rail ‐ Diesel                 ‐ ‐                   ‐                   ‐                   ‐                   ‐                   ‐                         

S4h ‐ Electric 1         484.58      16,236.22        2,521.32              24.09              74.74              30.52      1,226,661.92

S4h ‐ Diesel 484.58               16,236.22        2,521.32              24.09              74.74              30.52      1,226,661.92

S6h ‐ Electric 1           97.16        3,232.25            516.14                4.81              15.64                6.73          246,171.82

S6h ‐ Diesel 97.16                   3,232.25            516.14                4.81              15.64                6.73          246,171.82

S6hsr 1           97.16        3,232.25            516.14                4.81              15.64                6.73          246,171.82

1 Assume No bulid and existing rail are all diesel fueled trains.

2 Southern options are in some cases projected to be higher emissions for some pollutants for the build options due to no rail or airplane travel in the existing

scenario or that which will be used in the future No Build Scenario.

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Existing 2013 Emissions Tons per year 1

Totals By Alternative

Existing 2013

Totals By Alternative
No Build 2035

VOC CO NOx SO2 PM10 PM2.5 CO2

Auto 17.16                  2,736.19         105.47          3.54        56.76             12.40              522,403

Bus 0.04                            0.32             1.12          0.01          0.11               0.04                  1,286

Airplane 0.02                            0.14             0.05          0.01          0.00               0.00                         19

Rail ‐ Electric 0.05                            0.26             0.52          0.32          0.04               0.03           1,126,794

Rail ‐ Diesel 3.17                       120.55         149.42          0.43          2.26               2.20                46,263

Total           20.39       2,857.20         256.06          3.98        59.13             14.63        569,971.59

Auto 24.07                  3,390.53         136.90          4.75        75.25             15.93              702,131

Bus 0.26                            1.91             6.61          0.06          0.65               0.22                  7,689

Airplane 0.22                            2.04             0.79          0.12          0.02               0.02                       280

Rail ‐ Electric 0.20                            2.52             2.42          3.85          0.28               0.22           1,211,577

Rail ‐ Diesel 19.22                     731.17         906.27          2.58        13.73             13.32              280,594

Auto 24.67                  3,475.46         140.32          4.87        77.13             16.33              719,718

Bus 0.26                            1.91             6.61          0.06          0.65               0.22                  7,689

Airplane 0.22                            2.04             0.79          0.12          0.02               0.02                       280

Rail ‐ Electric 0.15                            1.89             1.82          2.88          0.21               0.16           1,211,577

Rail ‐ Diesel 14.42                     548.37         679.70          1.93        10.30               9.99              210,445

Auto 24.12                  3,398.14         137.20          4.76        75.42             15.96              703,705

Bus 0.26                            1.91             6.61          0.06          0.65               0.22                  7,689

Airplane 0.22                            2.04             0.79          0.12          0.02               0.02                       280

Rail ‐ Electric 0.18                            2.21             2.12          3.37          0.25               0.19           1,211,577

Rail ‐ Diesel 16.82                     639.77         792.98          2.26        12.01             11.65              245,520

Auto 23.97                  3,376.52         136.33          4.73        74.94             15.86              699,228

Bus 0.26                            1.91             6.61          0.06          0.65               0.22                  7,689

Airplane 0.22                            2.04             0.79          0.12          0.02               0.02                       280

Rail ‐ Electric 0.20                            2.52             2.42          3.85          0.28               0.22           1,211,577

Rail ‐ Diesel 19.22                     731.17         906.27          2.58        13.73             13.32              280,594

C4Ahsr 1           43.77       4,125.65      1,050.57          7.52        89.65             29.49        990,693.53

C4Ah ‐ Electric 1           25.30      3,481.31        149.55          7.95       78.02             16.73     1,939,263.75

CAAh‐Diesel 1           39.57       4,027.79         827.43          7.00        88.10             26.56        938,132.45

C4Bhsr 1           41.43       4,041.86         937.59          7.21        88.10             27.86        957,193.86

C4Chsr 1           43.67       4,111.64      1,050.00          7.50        89.34             29.42        987,790.73

Auto 82.28                12,943.27         435.12        16.22      260.21             57.26           2,400,800

Bus 0.27                            2.03             6.63          0.07          0.69               0.24                  8,174

Airplane                ‐ ‐                 ‐                ‐             ‐             ‐                  ‐                       

Rail ‐ Electric                ‐ ‐                 ‐                ‐             ‐             ‐                  ‐                       

Rail ‐ Diesel                ‐ ‐                 ‐                ‐             ‐             ‐                  ‐                       

Auto 8.30                    1,306.32           43.91          1.64        26.26               5.78              242,304

Bus 0.13                            0.94             3.07          0.03          0.32               0.11                  3,779

Airplane                ‐ ‐                 ‐                ‐             ‐             ‐                  ‐                       

Rail ‐ Electric                ‐ ‐                 ‐                ‐             ‐             ‐                  ‐                       

Rail ‐ Diesel                ‐ ‐                 ‐                ‐             ‐             ‐                  ‐                       

Auto 8.30                    1,306.32           43.91          1.64        26.26               5.78              242,304

Bus 0.13                            0.94             3.07          0.03          0.32               0.11                  3,779

Airplane                ‐ ‐                 ‐                ‐             ‐             ‐                  ‐                       

Rail ‐ Electric                ‐ ‐                 ‐                ‐             ‐             ‐                  ‐                       

Rail ‐ Diesel                ‐ ‐                 ‐                ‐             ‐             ‐                  ‐                       

S4h ‐ Electric 1           82.55     12,945.30         441.75        16.29      260.90             57.50     2,408,974.13

S4h ‐ Diesel 82.55                12,945.30         441.75        16.29      260.90             57.50     2,408,974.13

S6h ‐ Electric 1             8.43       1,307.25           46.98          1.67        26.58               5.89        246,083.02

S6h ‐ Diesel 8.43                    1,307.25           46.98          1.67        26.58               5.89        246,083.02

S6hsr 1             8.43       1,307.25           46.98          1.67        26.58               5.89        246,083.02

1 Assume No bulid and existing rail are all diesel fueled trains.

2 Southern options are in some cases projected to be higher emissions for some pollutants for the build options due to no rail or airplane

travel in the existing scenario or that which will be used in the future No Build Scenario.

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No Build 2035 Emissions Tons per year 1

Totals By Alternative

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Totals By Alternative
Build 2035

VOC CO NOx SO2 PM10 PM2.5 CO2

Auto 17.06                      2,720.20     104.85          3.52       56.42             12.32              519,351

Bus 0.04                                0.32          1.12          0.01          0.11               0.04                  1,286

Airplane 0.02                                0.14          0.05          0.01          0.00               0.00                         19

Rail ‐ Electric 0.03                                0.17          0.33          0.20          0.02               0.02              717,051

Rail ‐ Diesel 3.17                            120.55     149.42          0.43          2.26               2.20                46,263

Total             20.29         2,841.21     255.45          3.96       58.80             14.56        566,919.29

Auto 22.01                      3,100.06     125.17          4.35       68.80             14.56              641,978

Bus 0.26                                1.91          6.61          0.06          0.65               0.22                  7,689

Airplane 0.22                                2.04          0.79          0.12          0.02               0.02                       280

Rail ‐ Electric 0.04                                0.48          0.46          0.73          0.05               0.04              230,300

Rail ‐ Diesel 3.65                            138.98     172.27          0.49          2.61               2.53                53,336

Auto 23.90                      3,366.35     135.92          4.72       74.71             15.81              697,123

Bus 0.26                                1.91          6.61          0.06          0.65               0.22                  7,689

Airplane 0.22                                2.04          0.79          0.12          0.02               0.02                       280

Rail ‐ Electric 0.05                                0.59          0.57          0.91          0.07               0.05              380,495

Rail ‐ Diesel 4.53                            172.22     213.46          0.61          3.23               3.14                66,090

Auto 21.91                      3,085.96     124.60          4.33       68.49             14.50              639,058

Bus 0.26                                1.91          6.61          0.06          0.65               0.22                  7,689

Airplane 0.22                                2.04          0.79          0.12          0.02               0.02                       280

Rail ‐ Electric 0.04                                0.46          0.45          0.71          0.05               0.04              254,331

Rail ‐ Diesel 3.53                            134.30     166.46          0.47          2.52               2.45                51,539

Auto 22.24                      3,132.25     126.47          4.39       69.52             14.71              648,645

Bus 0.26                                1.91          6.61          0.06          0.65               0.22                  7,689

Airplane 0.22                                2.04          0.79          0.12          0.02               0.02                       280

Rail ‐ Electric 0.05                                0.58          0.56          0.89          0.07               0.05              280,365

Rail ‐ Diesel 4.45                            169.20     209.71          0.60          3.18               3.08                64,931

C4Ahsr             22.53         3,104.49     133.03          5.27       69.53             14.85        880,246.47

C4Ah ‐ Electric             24.43         3,370.90     143.89          5.81       75.45             16.11     1,085,587.36

CAAh‐Diesel             28.91         3,542.52     356.78          5.52       78.62             19.19        771,182.49

C4Bhsr             22.42         3,090.38     132.45          5.22       69.21             14.78        901,357.61

C4Chsr             22.76         3,136.79     134.43          5.47       70.25             15.01        936,978.50

Auto 82.12                    12,917.74     434.26       16.19     259.69             57.15           2,396,066

Bus 0.13                                0.94          3.07          0.03          0.32               0.11                  3,779

Airplane                  ‐ ‐                    ‐            ‐            ‐            ‐                  ‐                       

Rail ‐ Electric 0.04                                0.45          0.43          0.69          0.05               0.04              576,751

Rail ‐ Diesel 3.43                            130.52     161.78          0.46          2.45               2.38                50,089

Auto 7.94                        1,249.10       41.99          1.57       25.11               5.53              231,691

Bus 0.13                                0.94          3.07          0.03          0.32               0.11                  3,779

Airplane                  ‐ ‐                    ‐            ‐            ‐            ‐                  ‐                       

Rail ‐ Electric 0.01                                0.16          0.15          0.24          0.02               0.01              202,263

Rail ‐ Diesel 1.20                              45.77       56.74          0.16          0.86               0.83                17,566

Auto 7.81                        1,229.16       41.32          1.54       24.71               5.44              227,993

Bus 0.13                                0.94          3.07          0.03          0.32               0.11                  3,779

Airplane                  ‐ ‐                    ‐            ‐            ‐            ‐                  ‐                       

Rail ‐ Electric 0.01                                0.18          0.17          0.27          0.02               0.02              112,146

Rail ‐ Diesel 1.33                              50.76       62.91          0.18          0.95               0.92                19,479

S4h ‐ Electric 82.28                    12,919.13     437.76       16.91     260.06             57.30     2,976,595.54

S4h ‐ Diesel 85.67                    13,049.20     599.11       16.68     262.46             59.64     2,449,934.47

S6h ‐ Electric 8.08                        1,250.20       45.21          1.84       25.45               5.65        437,733.88

S6h ‐ Diesel 9.27                        1,295.81     101.79          1.76       26.29               6.47        253,036.77

S6hsr 7.95                        1,230.28       44.56          1.84       25.05               5.56        343,918.58

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Totals By Alternative

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Build 2035 Emissions Tons per year

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Totals By Alternative
VOC CO NOx SO2 PM10 PM2.5 CO2

2013 256 7,271 2,257 11 66 45 619,797

2035 No Build 20 2,857 256 4 59 15 569,972

2035 Project Alterative 20 2,841 255 4 59 15 566,919

VOC CO NOx SO2 PM10 PM2.5 CO2

2013 261 7,096 2,312 12 67 45 647,748

2035 No Build 44 4,126 1,051 8 90 29 990,694

2035 Project Alterative 23 3,104 133 5 70 15 880,246

2013 223 7,248 1,326 12 41 19 1,814,722

2035 No Build 25 3,481 150 8 78 17 1,939,264

2035 Project Alterative 24 3,371 144 6 75 16 1,085,587

2013 234 7,294 1,578 12 47 25 620,683

2035 No Build 40 4,028 827 7 88 27 938,132

2035 Project Alterative 29 3,543 357 6 79 19 771,182

2013 226 7,014 1,529 12 46 24 597,632

2035 No Build 41 4,042 938 7 88 28 957,194

2035 Project Alterative 22 3,090 132 5 69 15 901,358

2013 225 6,972 1,521 12 46 24 594,172

2035 No Build 44 4,112 1,050 8 89 29 987,791

2035 Project Alterative 23 3,137 134 5 70 15 936,978

VOC CO NOx SO2 PM10 PM2.5 CO2

2013 485 16,236 2,521 24 75 31 1,226,662

2035 No Build 83 12,945 442 16 261 57 2,408,974

2035 Project Alterative 82 12,919 438 17 260 57 2,976,596

2013 485 16,236 2,521 24 75 31 1,226,662

2035 No Build 83 12,945 442 16 261 57 2,408,974

2035 Project Alterative 86 13,049 599 17 262 60 2,449,934

2013 97 3,232 516 5 16 7 246,172

2035 No Build 8 1,307 47 2 27 6 246,083

2035 Project Alterative 8 1,250 45 2 25 6 437,734

2013 97 3,232 516 5 16 7 246,172

2035 No Build 8 1,307 47 2 27 6 246,083

2035 Project Alterative 9 1,296 102 2 26 6 253,037

2013 97 3,232 516 5 16 7 246,172

2035 No Build 8 1,307 47 2 27 6 246,083

2035 Project Alterative 8 1,230 45 2 25 6 343,919

S4HRSR ‐ SRSR ‐ Electric : Emissions Tons per year

S4HRSR ‐ SRSR ‐ Diesel : Emissions Tons per year

S6 HRSR ‐ HRSR‐ Electric : Emissions Tons per year

N4A ‐ Conventional: Emissions Tons per year

Evaluation Years

Evaluation Years C4AHDR ‐ HSR : Emissions Tons per year

C4AH ‐ HRSR‐ Electric : Emissions Tons per year

C4BHSR ‐ HSR: Emissions Tons per year

C4AH ‐ HRSR‐ Diesel : Emissions Tons per year

S6HSR ‐ HSR: Emissions Tons per year

S6 HRSR ‐ HRSR‐ Diesel : Emissions Tons per year

C4C HSR ‐ HSR: Emissions Tons per year

Evaluation Years
Scenario VMT1 (mi) VOC CO NOx SO2 PM10 PM2.5 CO2 

Auto Existing 2013 1,348,987,339.03 209.04 6,890.87 1,208.80 11.18 36.12 15.43 566,737

Auto No Build 2035 2,742,367,985.49 24.07 3,390.53 136.90 4.75 75.25 15.93 702,130

Auto C4A True High 2035 2,507,423,895.17 22.01 3,100.06 125.17 4.35 68.80 14.56 641,977

Auto Existing 2013 1,415,866,197.29 219.41 7,232.50 1,268.73 11.73 37.91 16.19 594,834

Auto No Build 2035 2,811,060,424.80 24.67 3,475.46 140.32 4.87 77.13 16.33 719,717

Auto C4A Higher 2035 2,722,809,840.23 23.90 3,366.35 135.92 4.72 74.71 15.81 697,123

Auto Existing 2013 1,361,000,146.42 210.91 6,952.24 1,219.57 11.28 36.44 15.57 571,784Auto No Build 2035 2,748,517,875.66 24.12 3,398.14 137.20 4.76 75.42 15.96 703,705

Auto C4B True High 2035 2,496,018,504.59 21.91 3,085.96 124.60 4.33 68.49 14.50 639,057

Auto Existing 2013 1,352,763,459.19 209.63 6,910.16 1,212.19 11.21 36.22 15.47 568,323

Auto No Build 2035 2,731,030,269.46 23.97 3,376.52 136.33 4.73 74.94 15.86 699,227

Auto C4C True High 2035 2,533,463,242.17 22.24 3,132.25 126.47 4.39 69.52 14.71 648,644

Scenario VMT (mi) VOC CO NOx SO2 PM10 PM2.5 CO2 Auto Existing 2013 1,303,329,271.33 206.38 7,078.95 1,201.45 10.76 37.77 17.45 545,734

Auto No Build 2035 2,047,593,985.09 17.16 2,736.19 105.47 3.54 56.76 12.40 522,403

Auto N4A 2035 2,035,630,280.60 17.06 2,720.20 104.85 3.52 56.42 12.32 519,350

Scenario VMT (mi) VOC CO NOx SO2 PM10 PM2.5 CO2 Auto Existing 2013 2,895,896,201.35 481.53 16,222.32 2,465.25 24.02 71.79 28.03 1,218,125

Auto No Build 2035 9,364,781,442.91 82.28 12,943.27 435.12 16.22 260.21 57.26 2,400,800

Auto S4 Higher 2035 9,346,313,853.53 82.12 12,917.74 434.26 16.19 259.69 57.15 2,396,065

Auto Existing 2013 575,850,908.97 95.75 3,225.82 490.22 4.78 14.27 5.57 242,225

Auto No Build 2035 945,152,133.94 8.30 1,306.32 43.91 1.64 26.26 5.78 242,303

Auto S6 Higher 2035 903,756,611.46 7.94 1,249.10 41.99 1.57 25.11 5.53 231,691

Auto Existing 2013 575,850,908.97 95.75 3,225.82 490.22 4.78 14.27 5.57 242,225Auto No Build 2035 945,152,133.94 8.30 1,306.32 43.91 1.64 26.26 5.78 242,303

Auto S6 True High 2035 889,331,732.36 7.81 1,229.16 41.32 1.54 24.71 5.44 227,993

Notes:Table A‐1 ‐ Passenger Vehicle Emissions 2013 and 2035 (tons/yr)

1 VMT as defined in the SDG TOPRS Values 20160301: TOPRS Phase 3, PMT, VMT, Mode Share, dated March 01, 2016.

Emission factors from MOVES model, for passenger vehicles and buses, for scenario year 2013 (56 mph) and 2035 (48 mph), for Canadian County, OK, Dallas Count

Canadian County is associated with the Norhtern Section, Dallas County is associated with the Central Section, and Cameron County is associated with the Souther

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Central Section

Northern Section

Southern Section
Scenario VMT (mi)1 VOC CO NOx SO2 PM10 PM2.5 CO2 

Bus Existing 2013 4,624,200.00 2.87 13.09 55.90 0.07 2.78 2.35 8,030

Bus No Build 2035 4,624,200.00 0.26 1.91 6.61 0.06 0.65 0.22 7,689

Bus C4A True High 2035 4,624,200.00 0.26 1.91 6.61 0.06 0.65 0.22 7,689

Bus Existing 2013 4,624,200.00 2.87 13.09 55.90 0.07 2.78 2.35 8,030

Bus No Build 2035 4,624,200.00 0.26 1.91 6.61 0.06 0.65 0.22 7,689

Bus C4A Higher 2035 4,624,200.00 0.26 1.91 6.61 0.06 0.65 0.22 7,689

Bus Existing 2013 4,624,200.00 2.87 13.09 55.90 0.07 2.78 2.35 8,030

Bus No Build 2035 4,624,200.00 0.26 1.91 6.61 0.06 0.65 0.22 7,689

Bus C4B True High 2035 4,624,200.00 0.26 1.91 6.61 0.06 0.65 0.22 7,689

Bus Existing 2013 4,624,200.00 2.87 13.09 55.90 0.07 2.78 2.35 8,030

Bus No Build 2035 4,624,200.00 0.26 1.91 6.61 0.06 0.65 0.22 7,689

Bus C4C True High 2035 4,624,200.00 0.26 1.91 6.61 0.06 0.65 0.22 7,689

Scenario VMT (mi)1 VOC CO NOx SO2 PM10 PM2.5 CO2 

Bus Existing 2013 776,412.00 0.48 2.20 9.46 0.01 0.47 0.39 1,343

Bus No Build 2035 776,412.00 0.04 0.32 1.12 0.01 0.11 0.04 1,286

Bus N4A 2035 776,412.00 0.04 0.32 1.12 0.01 0.11 0.04 1,286

Scenario VMT (mi)1 VOC CO NOx SO2 PM10 PM2.5 CO2 

Bus Existing 2013 4,909,200.00 3.05 13.90 56.07 0.07 2.95 2.49 8,535

Bus No Build 2035 4,909,200.00 0.27 2.03 6.63 0.07 0.69 0.24 8,174

Bus S4 Higher 2035 4,909,200.00 0.27 2.03 6.63 0.07 0.69 0.24 8,174

Bus Existing 2013 2,269,800.00 1.41 6.43 25.92 0.03 1.36 1.15 3,946

Bus No Build 2035 2,269,800.00 0.13 0.94 3.07 0.03 0.32 0.11 3,779

Bus S6 Higher 2035 2,269,800.00 0.13 0.94 3.07 0.03 0.32 0.11 3,779

Bus Existing 2013 2,269,800.00 1.41 6.43 25.92 0.03 1.36 1.15 3,946

Bus No Build 2035 2,269,800.00 0.13 0.94 3.07 0.03 0.32 0.11 3,779

Bus S6 True High 2035 2,269,800.00 0.13 0.94 3.07 0.03 0.32 0.11 3,779

Table A‐2 ‐ Intercity Bus Emissions 2013 and 2035 (tons/yr)

Notes:

1 VMT as defined in the SDG TOPRS Values 20160301: TOPRS Phase 3, PMT, VMT, Mode Share, dated March 01, 2016.

Emission factors from MOVES model, for passenger vehicles and buses, for scenario year 2013 (56 mph) and 2035 (48 mph), for Canadian County, OK 

County, TX (central region), and Cameron County, TX (southern region).

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C4BhsrC4Chsr

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Central SectionNorthern Section

Southern Section
Scenario Airplanes/Day2 VOC CO NOx SO2 PM10 PM2.5 CO2

Airplane Existing 2013 118 0.24 2.61 0.85 0.12 0.02 0.02 2

Airplane No Build 2035 118 0.22 2.04 0.79 0.12 0.02 0.02 2

Airplane C4A True High 2035 118 0.22 2.04 0.79 0.12 0.02 0.02 2

Airplane Existing 2013 118 0.24 2.61 0.85 0.12 0.02 0.02 2

Airplane No Build 2035 118 0.22 2.04 0.79 0.12 0.02 0.02 2

Airplane C4A Higher 2035 118 0.22 2.04 0.79 0.12 0.02 0.02 2

Airplane Existing 2013 118 0.24 2.61 0.85 0.12 0.02 0.02 2

Airplane No Build 2035 118 0.22 2.04 0.79 0.12 0.02 0.02 2

Airplane C4B True High 2035 118 0.22 2.04 0.79 0.12 0.02 0.02 2

Airplane Existing 2013 118 0.24 2.61 0.85 0.12 0.02 0.02 2

Airplane No Build 2035 118 0.22 2.04 0.79 0.12 0.02 0.02 2

Airplane C4C True High 2035 118 0.22 2.04 0.79 0.12 0.02 0.02 2

Scenario Airplanes/Day2 VOC CO NOx SO2 PM10 PM2.5 CO2

Airplane Existing 2013 8 0.02 0.18 0.06 0.01 0.00 0.00 

Airplane No Build 2035 8 0.02 0.14 0.05 0.01 0.00 0.00 

Airplane N4A 2035 8 0.02 0.14 0.05 0.01 0.00 0.00 

Scenario Airplanes/Day2 VOC CO NOx SO2 PM10 PM2.5 CO2

Airplane Existing 2013                               ‐ ‐                            ‐                ‐                 ‐                  ‐                  ‐                    

Airplane No Build 2035                               ‐ ‐                            ‐                ‐                 ‐                  ‐                  ‐                    

Airplane S4 Higher 2035                               ‐ ‐                            ‐                ‐                 ‐                  ‐                  ‐                    

Airplane Existing 2013                               ‐ ‐                            ‐                ‐                 ‐                  ‐                  ‐                    

Airplane No Build 2035                               ‐ ‐                            ‐                ‐                 ‐                  ‐                  ‐                    

Airplane S6 Higher 2035                               ‐ ‐                            ‐                ‐                 ‐                  ‐                  ‐                    

Airplane Existing 2013                               ‐ ‐                            ‐                ‐                 ‐                  ‐                  ‐                    

Airplane No Build 2035                               ‐ ‐                            ‐                ‐                 ‐                  ‐                  ‐                    

Airplane S6 True High 2035                               ‐ ‐                            ‐                ‐                 ‐                  ‐                  ‐                    

Notes:

1 Airplane emissions include approach, climb out, takeoff, and taxi. It does not include emissions at altitude.2 Airplanes per day as defined in the SDG TOPRS Values 20160301: TOPRS Phase 3, LOS tabs, dated March 01, 2016.3 No airplanes were shown in the southern region, based on the SDG TOPS LOS tabs.

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Table A‐3 ‐ Airplane Emissions 2013 and 2035 (tons/yr) 1

Central SectionFuel type source: REDCOM, Commercial Aviation Fuels, TARDEC. December 2011, JP8 Fuels.

GHG emission factor from World Resources Institute (2008). GHG Protocol tool for mobile combustion. Version 2.0. Jet Fuel. http://www.ghgprotocol.org/calculation‐

tools/service‐sector

Emission factors of criterial pollutants are based on default values for a Boeing 737‐300 series airplane, from the EDMS model. Emissions include airplanes, GSE, and AP

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Northern Section

Southern Section

Scenario Power (MW)1

1‐Way

Trains/day 2 Minutes Increased MWh VOC CO NOx SO2 PM10 

Rail Existing 2013 9.60 2 605 194 0.01 0.16 0.15 0.24 

Rail No Build 2035 9.60 32 605 3,098 0.20 2.52 2.42 3.85 

Rail C4A True High 2035 9.60 32 115 589 0.04 0.48 0.46 0.73 

Rail Existing 2013 9.60 2 605 194 0.01 0.16 0.15 0.24 Rail No Build 2035 9.60 24 605 2,323 0.15 1.89 1.82 2.88 

Rail C4A Higher 2035 9.60 24 190 730 0.05 0.59 0.57 0.91 

Rail Existing 2013 9.60 2 605 194 0.01 0.16 0.15 0.24 Rail No Build 2035 9.60 28 605 2,710 0.18 2.21 2.12 3.37 

Rail C4B True High 2035 9.60 28 127 569 0.04 0.46 0.45 0.71 

Rail Existing 2013 9.60 2 605 194 0.01 0.16 0.15 0.24 Rail No Build 2035 9.60 32 605 3,098 0.20 2.52 2.42 3.85 

Rail C4C True High 2035 9.60 32 140 717 0.05 0.58 0.56 0.89 

Scenario Power (MW)1

1‐Way

Trains/day 2 Minutes

Increased

MWh VOC CO NOx SO2 PM10 

Rail Existing 2013 9.60 12 418 803 0.05 0.26 0.52 0.32 Rail No Build 2035 9.60 12 418 803 0.05 0.26 0.52 0.32 

Rail N4A 2035 9.60 12 266 511 0.03 0.17 0.33 0.20 

Scenario Power (MW)1

1‐Way

Trains/day 2 Minutes Increased MWh VOC CO NOx SO2 PM10 

Rail Existing 2013                                ‐ 9.60                       ‐                    ‐ ‐              ‐                         ‐                     ‐                      

                  

Rail No Build 2035                                ‐ 9.60                       ‐                    ‐ ‐              ‐                         ‐                     ‐                      

                  

Rail S4 Higher 2035 9.60 12 288 553 0.04 0.45 0.43 0.69 

Rail Existing 2013                                ‐ 9.60                       ‐                    ‐ ‐              ‐                         ‐                     ‐                      

                  

Rail No Build 2035                                ‐ 9.60                       ‐                    ‐ ‐              ‐                         ‐                     ‐                      

                  

Rail S6 Higher 2035 9.60 12 101 194 0.01 0.16 0.15 0.24 Rail Existing 2013                                ‐ 9.60                       ‐                    ‐ ‐              ‐                         ‐                     ‐                      

                  

Rail No Build 2035                                ‐ 9.60                       ‐                    ‐ ‐              ‐                         ‐                     ‐                      

                  

Rail S6 True High 2035 9.60 24 56 215 0.01 0.18 0.17 0.27 

Notes:Criteria Pollutant Emission Factors are from the most recent NEI State summary: National Emissions Inventory (NEI) by State, 2011. Emission Inventory from combustion sources are represen

bin/broker?_service=data&_debug=0&_program=dataprog.state_1.sas&pol=PM25_PRI&stfips=40GHG Emission factors obtained from eGRID2012 Summary Tables. 2012 eGrid Subregion Resource Mix, Data from 2012. Data not avaliable for 2011. https://www.epa.gov/sites/production/f

Table A‐4 ‐ Electric Locomotive Emissions 2013 and 2035 (tons/yr)

Central Section

Northern Section

Southern Section

C4Ahsr

C4Ah

1 Electric‐powered train set rating is based on email provided by Bruce Horowitz, email dated 2/28/16. "Based on Bombardier's current European UIC Standard HSR Distributed Power Trains

scenarios in the central section, and the single true HSR scenario in the southern section, the power for our proposed fixed consist 8‐car trainset is 9600 KwH or roughly 10 MW."

2 Trains per day is based on the TOPRS schedules in Service Development Plan: Narrative on Initial Service Schedule and Operating Assumptions Texas‐Oklahoma Passenger Rail Study – Servic

C4BhsrC4Chsr

N4Ac

S4hS6h

S6hsr

Central Section

Scenario

Number of

Trains1

Travel Time2

(min/day) VOC CO NOx SO2 PM10 

Rail Existing 2013 2 605 11.84 45.70 252.31 0.16 6.69 

Rail No Build 2035 32 605 19.22 731.17 906.27 2.58 13.73 

Rail C4A True High 2035 32 115 3.65 138.98 172.27 0.49 2.61 

Rail Existing 2013 2 605 11.84 45.70 252.31 0.16 6.69 

Rail No Build 2035 24 605 14.42 548.37 679.70 1.93 10.30 

Rail C4A Higher 2035 24 190 4.53 172.22 213.46 0.61 3.23 

Rail Existing 2013 2 605 11.84 45.70 252.31 0.16 6.69 

Rail No Build 2035 28 605 16.82 639.77 792.98 2.26 12.01 

Rail C4B True High 2035 28 127 3.53 134.30 166.46 0.47 2.52 

Rail Existing 2013 2 605 11.84 45.70 252.31 0.16 6.69 

Rail No Build 2035 32 605 19.22 731.17 906.27 2.58 13.73 

Rail C4C True High 2035 32 140 4.45 169.20 209.71 0.60 3.18 

Scenario

Number of

Trains1

Travel Time2

(min/day) VOC CO NOx SO2 PM10 

Rail Existing 2013 12 418 49.10 189.44 1,045.95 0.67 27.75 

Rail No Build 2035 12 418 4.98 189.44 234.81 0.67 3.56 

Rail N4A 2035 12 266 3.17 120.55 149.42 0.43 2.26 

Scenario

Number of

Trains1

Travel Time2

(min/day) VOC CO NOx SO2 PM10 

Rail Existing 2013 0                                  ‐ ‐                          ‐                ‐                       ‐                         ‐                       

Rail No Build 2035 0                                  ‐ ‐                          ‐                ‐                       ‐                         ‐                       

Rail S4 Higher 2035 12 288 3.43 130.52 162 0.46 2.45 

Rail Existing 2013 0                                  ‐ ‐                          ‐                ‐                       ‐                         ‐                       

Rail No Build 2035 0                                  ‐ ‐                          ‐                ‐                       ‐                         ‐                       

Rail S6 Higher 2035 12 101 1.20 45.77 57 0.16 0.86 

Rail Existing 2013 0                                  ‐ ‐                          ‐                ‐                       ‐                         ‐                       

Rail No Build 2035 0                                  ‐ ‐                          ‐                ‐                       ‐                         ‐                       

Rail S6 True High 2035 24 56 1.33 50.76 63 0.18 0.95 

Notes:Hourly schedules as defined in the SDG TOPRS Values 20160301: TOPRS Phase 3, TravelTime tab, dated March 01, 2016.

Emission factors are based on Office of Transportation and Air Quality, EPA‐420‐F‐09‐025, dated April 2009. PM2.5 was estimated at 97% of PM10 (Page 4, other p

20.8 hp‐hr/gal, for Passenger Locomotives is from Table 3 of this document and was used to convert the emission factors.

Diesel Train horsepower provided by Bruce Horowitz, email dated 2/25/16. The High‐Performance Diesel Loco HP, based on the currently contracted (and under c

Siemens Passenger Caltrans/IDOT 125 model: 4,400 HP

Table A‐5 ‐ Diesel Locomotive Emissions 2013 and 2035 (tons/yr)

1 Number of trains for No build was set equal to number of trains for bulid alternative to account for population growth, except for in the Souther Section where th2 Travel time for northern route based on time from Okalhoma city to Dallas‐Fort Worth, central cention from Dallas to San Antonio, and Southern Section based o

Northern Section

Southern Section

S6h

S6hsr

C4Ahsr

C4Ah

C4Bhsr

C4Chsr

N4Ac

S4h